Roast Sirloin, Mushrooms, Potatoes & Mustard Butter

Directions

• First make the mustard butter by whisking together the cream cheese, butter, mustards and salt until smooth and well blended. Roll into a log shape, cover with cling film and place in the fridge or freezer to firm up.
• Score the fatty rind of the meat lightly, then rub the meat well with lemon juice and a generous amount of olive oil.
• Combine the stock powder, pepper, thyme and 20 ml of the rosemary. Spread on a board and roll the meat all over in the mixture, pressing it down firmly so that the mixture sticks to the meat. Set aside.
• Toss the potato wedges and mushrooms well with a generous slug of olive oil, some lemon juice, a generous sprinkling of beef stock powder, the extra rosemary and black pepper to taste. Place the mixture in the bottom of a large roasting pan.
• Place the meat on a rack suspended above the vegetables with the fatty side facing up.
• Roast in a preheated oven at 230°C for 20 minutes. Shake pan to toss the mushrooms and potatoes, then turn the oven off. Allow the pan to remain in the oven until the meat is done to your liking: for medium, rest the meat in the oven for 20 minutes, and if you like it medium-rare, rest the meat in the oven for 10 minutes.
• Serve the meat sliced and topped with thick slices of the mustard butter, alongside the mushrooms and potatoes and some fresh rocket leaves splashed with lemon-infused olive oil.