My guide for how to perfectly cook Air Fryer Large Flat Mushrooms includes my tips for making sure the tasty portobellos are properly cooked through but beautifully juicy and not remotely dry or shrivelled! Perfect for serving with breakfasts, steak dinners, adding to burgers, or simply serving as a side dish.
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I love adding mushrooms to meals, they’re quick to cook, easy to eat and absolutely delicious. I also like to vary the kinds of mushrooms that I serve up.
How to Serve
Mushrooms are incredibly versatile. They easily fit in with any cuisine. The only time I tend to avoid incorporating them into a meal is with seafood. As much as I love air frying fish and shellfish, I just don’t love the flavour combo.
I’m also not a massive fan of eating cooked mushrooms cold. But other than that, the world is your oyster.
With the photos on this page, I chose to serve the mushrooms with an English style “fried” breakfast along with the following:
For more air fried breakfast recipes, check out my collection page:
Air Fryer Full English Breakfast Recipes
Find all of my air fried breakfast recipes in on place. Mix and match to your hearts desire or just go for it and make them all!
Featuring thick and thin back bacon, tasty sausages, simple hash browns, delicious mushrooms and grilled tomatoes.
Add the mushrooms to a classic griddled steak dinner along with air fried chippy chips, garden peas and some onion rings. Or indeed add to any grilled meat meal such as when making air fried gammon steaks or meats like pork belly slices.
Or make an Asian inspired meal and add air fried whole mushrooms to your pork ramen, serve with sticky rice, salt and chili edamame beans and sweet chilli chicken thigh fillets.
Ingredients
Mushrooms
“Large Flat Mushrooms” is how I’ve noticed that these Portobello mushrooms are now often labelled here in the UK in supermarkets. To be fair it is an accurate description. Wherever you are, it isn’t going to be difficult to determine what kind of mushroom you’re looking for. It really doesn’t matter how they’re labelled.
What I do look for is that the mushrooms are firm and dry. Mushrooms that are getting soft wet spots in places are getting past their best. By all means, do cook and eat them, don’t waste mushrooms like this, but I try not to buy them in that state unless heavily discounted.
If you do find yourself with less than perfect specimens, I usually find that peeling away the outer skin will give them a nice little refresh. I also often cut the very end of the stalk if that is looking less than fresh.
You shouldn’t wash mushrooms with water as they are little sponges. If there are any specks of dirt, simply brush them off or use paper towels for anything more stubborn.
Butter
Butter is best friends with mushrooms. I only use salted butter so if you are using something unsalted, you may wish to add more seasoning.
It is preferable to use proper block butter here but if you need to use something spreadable, it won’t be the end of the world. If using some kind of margarine, just bear in mind that the flavour will be present in the finished cooked mushrooms. If you aren’t sure, it may be best to use oil instead.
I melt the butter before brushing it onto the mushrooms. This means that they get a really even coat and you don’t end up with dry patches. If you wish to use oil instead of butter, I really do recommend brushing it on in the same way.
Another great substitute is to use garlic butter or another flavoured butter to add extra flavour. I wouldn’t be inclined to do this when serving for breakfast but absolutely would, and do, when serving with steaks etc.
Seasoning
As I often do, I’ve kept things very simple here and just used sea salt flakes to season the mushrooms. You can absolutely add different spices, herbs or flavours to complement your meal.
Try lemon zest, garlic salt and dried chilli flakes for a zesty kick. Or dried oregano, paprika, garlic, salt and cumin for a Tex-Mex or Mexican slant.
Allergen Information
This recipe is free from egg, gluten and nuts.
Dairy Free: To make a diary free version of this recipe, simply switch out the dairy butter for a plant based substitute or oil.
Please note that this recipe may contain other allergens not referred to above and any variations suggested have not been tested unless otherwise stated. For more information regarding any dietary information provided on this website, please refer to my Nutritional Disclaimer.
How Long to Air Fry Big Flat Mushrooms
I like to make sure that my mushrooms are really well cooked through. Not because they require it from a food safety point of view, but because they’re much nicer to eat when they’re lovely and soft all the way through. I’m not a fan of squeaky mushrooms. A longer cooking time also ensures that the butter and salt flavours truly penetrate the whole mushroom.
So to this end, I cooked my very fresh mushrooms which were circa 75g/2½oz each for a total of 18 minutes. 6 minutes with the stalk side up and then the remainder of the time top side up.
These were really what I would consider on the large side of large mushrooms. So if yours are smaller/thinner/older, you may find that they are soft and unctuous in as little as 12 minutes total cooking time. Just check and use your gut!
How to Air Fry Portobello Mushrooms From Frozen
Please don’t freeze the mushrooms if you are intending on air frying them whole like this. They don’t defrost with anything like the same texture as fresh mushrooms.
For the record you can freeze mushrooms but they’re best used in things like sauces and casseroles. But not grilling or air frying like this.
Leftovers – Storage & Reheating
Leftovers can be stored in an air-tight container in the fridge for several days. They will reheat in a few minutes back in the air fryer. A little dab of extra butter does not hurt at all when reheating. They won’t have quite the same texture as fresh so I wouldn’t cook them in advance on purpose unless you’re happy with this.
You can also freeze the cooked large mushrooms but as with fresh, I think they are best added to saucy dishes once defrosted.
Common Air Fryer Questions – A Brief Guide to Air Frying
- What exactly is an air fryer?
- What are the benefits of using an air fryer?
- Are all air fryers the same?
- Is an air fryer always better to use than an oven?
- Do air fryers need to be pre-heated?
- What is the best temperature to air fry at?
- What setting is best to use? Air fry, bake, dehydrate, etc…
- Can food be cooked from frozen in an air fryer?
- Can I reheat food in an air fryer?
- Are air fryer liners a good idea?
The Air Fried Feast Community
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What Exactly is an Air Fryer?
Very simply, an air fryer is a small convection (fan) oven. The benefit is that the hot air is circulated all around the food being cooked which speeds up the cooking time and cooks the food more evenly.
What are the Benefits of Using an Air Fryer?
Size, time and energy usage. Air fryers are ideal for cooking smaller quantities. Heating up a space that the food just fits into requires less energy and means that the heat source is much closer to the food. Combining these two things can speed up the cooking time.
Are all air fryers the same?
Nope! The term air fryer is now used very broadly. I consider there to be 4 main types:
Basket Air Fryers
These are what I would consider to be the most common, especially in the UK. A boxy type unit has a pull out drawer/basket. Food isn’t usually visible whilst cooking.
Some larger models have two drawers so different items can be cooked at different temperatures or for different times.
This is the type that you’ll see in the images in this recipe. I mostly use a Cosori Lite 3.8L (CAF-LI401S) with a 3.8 litre capacity. The square(ish) shaped basket is 21cm x 21cm and 24cm on the diagonal. It isn’t an overly expensive or fancy model.
I’ve also recommended to several friends and family the model with a slightly larger basket. This is the Cosori 4.7L (CAF-L501) with a 4.7 litre basket. The unit is no larger than the 3.8 litre model on the outside but does have a larger internal basket capacity. I’ve since bought this version to use for some recipes where my smaller model was just too small. I’ll always note this in the recipe.
Rotary Air Fryers
Round air fryers with a paddle in the centre that rotates to move the food. This is the type I used for years – the most common is a Tefal Actifry.
Rotary types are not usually good for recipes where the food is breaded, glazed, likely to break up or in a tray/container. They do however make the best chips and roasted veg.
My 2 in 1 version like the one I’ve linked also has a rotating tray for things that could be broken up by a paddle, but the height clearance with the lid isn’t deep enough to use it to cook some items like sausage rolls. I’ve now actually retired by Actifry in favour of having my two basket type fryers.
Mini Oven Air Fryers
These usually have a glass door, shelves and overall are really quite large. You can cook quite a decent quantity of food in them so are best if regularly cooking for multiple people. They often come with extra features like a rotisserie spit or kebab skewers.
Multicookers with Air Fryer Functions
Some like Ninja 11 in 1 and some of the earlier versions with a few less functions, have an air fryer option. They mostly operate the same as a basket fryer but the basket drops in the top rather than sliding in like a drawer.
Some electric pressure cookers like Instant Pots can also air fry when used with a specific lid.
Is an air fryer always better to use than an oven?
As much as I do love air frying, the honest answer to this is no. And the more detailed answer is that it will always depend on what you’re cooking, how much of it you’re cooking and what type and size of air fryer you have.
Once you need to cook in more than 2 batches, it often makes more sense to use an oven. If you already have the oven on to cook other items, it may make more sense to throw one more item in rather than using an additional appliance.
I don’t think either method is often necessarily better than the other. The important point to note is that there is absolutely no difference in the finished product.
Do Air Fryers Need to Be Pre-Heated?
The answer to this is rather annoying – it depends. It depends entirely on your model and type of air fryer. The best advice I can offer is to check your manual and follow their guidance. My Cosori models have a preheat function. I press a button and it heats at 205c/400f for 4 minutes.
It’s also worth noting that regardless of whether you are supposed to pre-heat or not, if you are cooking in batches, it is quite likely that anything after the first batch will cook a little quicker because of the retained heat. It is best to check on them before the cooking time is completed.
What is the best temperature to Air Fry at?
It will always depend on what you are cooking and from what state. All of my air fryer recipes don’t use temperatures above 200c/390f because many of the most common fryers in the UK don’t go above this. Mine goes to 230c/450f and I use this temperature a lot but it is no help for me to share recipes which many people can’t use.
What setting is best to use? Air fry, bake, dehydrate, etc…
Not all air fryers have different settings like this. When they do it usually relates to the fan speed. The default setting to use will always be “air fry” so unless something else is specifically stated in the recipe, always use the air fry option.
There are other air fryers that have an additional heating element which cooks from underneath rather than just the top. Just as with the other settings, unless you are using a recipe which states to use a second heating element, stick with just using the top down air fry option.
Of course if and when you become more confident with air frying, using recipes and the settings of your air fryer, you can start adapting them to suit.
Can Food Be Cooked From Frozen In An Air Fryer?
Absolutely! To cook from frozen you usually will need to reduce the cooking temperature and increase the time to make sure your food is cooked right through to the middle.
It is best to check my individual recipes for cooking from frozen advice as some items are a little different. And there are occasionally exceptions to the rule.
Can I Reheat Food In An Air Fryer?
Yes. As a general rule I reheat food for roughly 1/3 of the original cooking time at the same temperature. Or at 10 degrees lower for half the time for larger items.
Are Air Fryer Liners a Good Idea?
Unless otherwise stated, I do not use liners when air frying. Basket and rotary type air fryers are designed to be used without liners. Mini oven types will generally require some kind of tray like with a regular large oven although most come with crisper racks to use.
There are many air fryer liners available including quite thick silicone ones. These will affect the cooking times and possibly temperatures of your cooking/baking. I also don’t like how cooking juices are prevented from dripping through the basket rack. This can stop food from crisping all the way around.
When I do want to collect the juices, I mostly use some foil, or occasionally a foil tray which can be washed and reused.
If you do prefer to use them, once you have got a feel for how they affect your cooking and baking, you may need to make adjustments to the recipe accordingly.
More Air Fryer Recipes
All my recipes with instructions for how to cook or bake them in the air fryer can be found in my Air Fryer Recipe Index.
Don’t forget to let me know in the comments if you try making this recipe – I want to know what you think and if you made any substitutions, how did it turn out?
Still Have Questions?
Simple! Just contact me and I will do my best to help as quickly as I am able. Head over to my Contact Me page, any of my social media channels or post a comment at the bottom of this page and I’ll see what I can do.
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The Recipe
Air Fryer Large Flat Mushrooms (Portobello Recipe)
Equipment
Ingredients
- 4 Large Flat Mushrooms (Portobello) - circa 75g/2½oz each
- 30 g Salted Butter
- ¼ tsp Sea Salt Flakes
Instructions
- If your air fryer requires pre-heating, start this setting now.
- Prepare 4 Large Flat Mushrooms by brushing away any dirt (don't wash them) and make sure they are thoroughly dry.
- Melt 30g Salted Butter in a small bowl in the microwave or in a pan on the stove. You can alternatively do this in a small heatproof bowl in the air fryer.
- Brush the butter onto the tops of the mushrooms – be fairly generous.
- Brush the remaining butter onto the underside of the mushrooms – make sure to use all the butter.
- Season the tops of the mushrooms with roughly half of the ¼ tsp Sea Salt Flakes.
- Use tongs to place the mushrooms bottom side up in the air fryer basket.
- Season again with the remaining salt.
- Cook for 6 minutes at 200c/390f.
- Turn the mushrooms right side up and cook for a further 12 minutes at 180c/350f.
- Check the mushrooms are as soft/brown as you like them and cook for longer if you prefer.
- Serve!
Notes
- This recipe is tested in a Cosori Lite (CAF-LI401S) with a 3.8 litre capacity. The square(ish) shaped basket is 21cm x 21cm and 24cm on the diagonal.
- Not all models advise preheating is required. Please follow the recommended instructions for your model. Mine has a specific preheat setting which is 4 minutes at 205c.
- For this recipe, I can comfortably cook 4 very large mushrooms in the basket at one time.
- As all air fryer models are a little different, you may find that you can fit more or less in at a time. Some models include stacking shelves which will increase capacity.
- Required cooking times and temperatures can also vary between models and brands. If you know that your air fryer runs a little hotter than most recipes suggest, use a lower temperature. And vice versa. Equally if you find that food cooks more quickly in your machine than instructions usually state, reduce the cooking time (or check it earlier) and vice versa.
Cat says
So simple and they turned out perfectly!
Karen says
Really easy way to cook mushrooms. I added some garlic and they were delicious.