Name: Porcini-buttered roast beef sirloin with pickled peppercorn sauce
Prep time: 30 min
Cook time: 1 h 20 min
Total time: 1 h 50 min
Yield: Serves 6-8
Ingredients: 2kg boneless sirloin rolled and tied; 10g dried porcini mushrooms; 1 tsp black peppercorns; 50g unsalted butter softened; 2 tbsp rapeseed or vegetable oil; 6-8 shallots peeled and trimmed; 2 tbsp green peppercorns; 4 tbsp sherry vinegar; 2 large shallots finely chopped; 250ml beef or vegetable stock; 200ml double cream

One porcini-buttered roast beef sirloin with pickled peppercorn sauce on a serving plate

2kg boneless sirloin
rolled and tied
10g dried porcini mushrooms
1 tsp black peppercorns
50g unsalted butter
softened
2 tbsp rapeseed or vegetable oil
6-8 shallots
peeled and trimmed

For the green peppercorn sauce

2 tbsp green peppercorns
4 tbsp sherry vinegar
2 large shallots
finely chopped
250ml beef or vegetable stock
200ml double cream

Method

step 1
The night before, prepare the peppercorns for the sauce. Put the green peppercorns and vinegar in a small bowl, cover and leave at room temperature overnight.
step 2
The next day, pat the beef dry with kitchen paper, cover loosely, and leave for 1 hr at room temperature – this helps to ensure perfectly cooked meat later. Put the dried porcini mushrooms and black peppercorns in a small blender or spice grinder, and blitz to a powder. Mash with the butter and set aside.
step 3
Heat the oven to 230C/210C fan/gas 8. Season the sirloin all over with the sea salt. Heat the oil in a flameproof roasting tin or large frying pan over a high heat, and sear the beef, fat-side down, for 5-8 mins until some of the fat has rendered out and turned golden brown, then holding the beef with tongs, sear it on all sides for 2-3 mins until browned all over. Sit the browned beef in the roasting tin fat-side up and spoon out most of the fat (if you have rendered it in the tin). Spoon 2 tbsp of the rendered fat over the beef and reserve any leftover fat for making yorkshires. Arrange the shallots around the beef, turning to coat them in the fat.
step 4
Roast for 20 mins, then dot the porcini butter all over the beef and reduce the heat to 180C/160C fan/gas 4. Roast for another 40-50 mins for rare to medium-rare, or 1 hr for medium-well. If you have a meat thermometer, it should read 55C for medium-rare, or 65C for well done. Baste the meat in the butter from the tin, then transfer to a warm platter or board with the shallots. Cover and leave to rest for 20 mins.
step 5
To make the sauce, discard all but 4 tbsp fat from the tin and set the tin over a low heat (or transfer to a pan), and fry the chopped shallots for 6-8 mins until softened and translucent. Strain the pickled peppercorns, reserving the vinegar, and add to the pan along with the stock. Bring to a simmer and cook for 10 mins until reduced by about half, then whisk in the cream. Taste for seasoning, and add the reserved vinegar, 1 tsp at a time, to balance the acidity and creaminess (we used about 5 tsp). Simmer for another 5-6 mins until the sauce has thickened. Pour into a jug. Carve the beef and serve with the roasted shallots and sauce.