Preheat the oven to 190 degrees C.
Put a large pan on a medium high heat and place the sirloin fat side down and sear for 2 mins. Then sear all over the sirloin until it is evenly coloured.
Put the sliced onion, garlic and thyme into a roasting tray, add the beef and pour in the red wine. Cook for 40 mins per kilo for medium rare or 45 mins per kilo for medium. Alternatively you can check for an internal temperature of 55 degrees for medium rare.
Roast Rolled Sirloin with Red Wine Gravy
