Roast Beef Sirloin is a quick cook and flavour packed joint which is ideal for Sunday Lunch. Or any meal! My Sirloin of Beef recipe serves 4, takes just 60 minutes and comes with perfect beef gravy too. Don’t forget the Yorkshire puddings for the best roast beef dinner!
Turn the oven on to 250°c | 230°c fan | GM 4 | 480°f (or as high as it will go).
Cut both ends off 2 Onions and slice them in half so that the rings show. Peel them.
Add 1 tbsp Vegetable Oil to a small roasting tray, add the onion halves and turn them over in the oil to coat.
Pop into the oven to start roasting whilst it continues to heat and you sear the beef.
Put a skillet or frying pan onto the heat to get hot. The thicker the pan, the higher the heat. It want’s to be smoking within the next 3-4 minutes.
Prepare a 1.25kg Sirloin of Beef by drying it off with paper towel and trimming off any excess fatty pieces or gristle. Score the fat in a diamond pattern. Don’t cut all the way through if possible.
Rub the meat with 1 tbsp Vegetable Oil and then sprinkle on 2 tsp Sea Salt Flakes.
Turn the heat up to full on your pan and put the beef in flesh down. Don’t touch it for 3 minutes.
Use tongs to turn the meat over and sear the skin side for 3 to 4 minutes.
Take the onions out of the oven and spread them so they create a trivet for the beef to sit on.
Transfer the beef onto the onions and then put into the oven.
Cook for 20 minutes. You don’t need to poke or baste it in this time.
Meanwhile start the gravy by putting the kettle onto boil and tipping any juices and crispy bits from the frying pan into a small saucepan.
Add roughly 50ml Water to the pan whist it is still on the heat. Give it 30 seconds boiling and then also scrape that into the saucepan. This ensures that you are wasting no beef flavour.
Add 600ml Boiling Water and 1 tsp Beef Stock Concentrate to the saucepan and bring to the boil.
Meanwhile mix 4 tbsp Cornflour with enough water to make a loose paste.
Once the gravy is boiling, add the cornflour a little at a time whilst continually whisking it. Add more when it is boiling again and isn’t thick enough after 20 or so seconds. Cornflour is a funny beast and you might need more or less to get your desired thickness. You will be adding a little more liquid so make it slightly thicker that you want it at this point.
You can turn the heat off and set aside the gravy until the meat is cooked.
Once the meat has been cooking for 20 minutes, take it out the oven and make a cut in the underside to see how well done it is. 20 minutes at the highest temp should be cooked medium but the thickness of the joint will make a difference. If it is not cooked enough for you, put it back in the oven. But do remember that it will continue cooking as it rests so please don’t panic and overcook it.
Once cooked to your preference, take the beef and place it on a plate. Scrape all the onions and juices into the gravy saucepan. Don’t scrape any burnt bits as these will make the gravy taste burnt too but crispy caramelised bits are great for flavour.
Move the beef back to the roasting pan and cover with foil and a tea towel. Set it aside for no less than 15 minutes.
With 5 minutes to go, heat the gravy back up whilst whisking. Check the seasoning and add circa 1 tsp Sea Salt Flakes depending on your taste.
You can sieve the onion out of the gravy at this point. You don't need to but some people don't like bits in their gravy.
When the meat is rested, pour any resting juices into the gravy, and serve both the meat and gravy. You can strain the gravy if you don’t want the onion in it!
Step by Step Video
Important! If you have adjusted the serving size of this recipe, the cooking time will vary. A larger joint will take longer to cook and a smaller joint will take less. Don’t forget that the tin size will also need to be adjusted.