HORSERADISH SAUCE FOR ROAST BEEF RECIPES

Steps:

• Whisk crème fraîche (or sour cream) in a medium bowl until thickened and soft peaks start to form, 1-2 minutes. Fold in horseradish and peppercorns; season with salt and more horseradish, if desired. DO AHEAD Sauce can be made 3 days ahead. Cover; chill.
• Combine first 5 ingredients and rub all over meat, pressing to adhere. DO AHEAD Beef can be seasoned 1 day ahead. Wrap in plastic; chill. Let stand at room temperature for 1 hour before continuing.
• Preheat oven to 400°. Scatter rosemary over bottom of a large roasting pan.
• Heat oil and butter in a 12 inches cast-iron skillet over medium-high heat. Sear meat until brown on all sides, about 5 minutes. Transfer to prepared roasting pan.
• Roast meat until an instant-read thermometer inserted into thickest part of beef registers 125° for medium-rare, about 30 minutes. Transfer to a carving board. Let rest for 15 minutes. Thinly slice tenderloin. Serve with Horseradish Cream.
• To double or triple the recipe, sear the tenderloins one at a time, then arrange crosswise in roasting pan (cook time will be the same). Leave at least 1 inch-2 inches between pieces of meat.

Steps:

• Preheat the oven to 220°C/200°C fan/Gas 7.

  Season the fillet with plenty of salt and black pepper and rub with the oil.

  Place a large frying pan over a high heat until very hot. Fry the fillet on all sides until browned.

  Sit the fillet in the centre of a roasting tin and spread the mustard evenly over the top. Lay the rosemary sprigs around the fillet in the tin and drizzle the beef with oil. Roast in the oven for 20–25 minutes for medium rare (or only 15 minutes, if it is a long, thin fillet).

  Remove the beef from the oven and set aside on a board. Cover with foil and leave to rest for 15 minutes. (If serving cold, leave to cool completely, then wrap in more foil and place in the fridge.)

  Meanwhile, to make the sauce, measure the mayonnaise, crème fraîche and mustard into a bowl. Stir to combine, then add the horseradish. Season and mix to combine. Chill until ready to serve alongside the beef.

  Carve the beef into thick or thin slices and serve with the sauce alongside.

  Mary’s tips:

  Beef can be fried up to 8 hours ahead and roasted to serve. If serving cold, the fillet can be roasted, carved, reassembled into it’s original shape a day ahead and wrapped in cling film. This prevents the pink slices from turning grey. Ideally carve just before serving.

  Not for freezing.

  It is important to ask for a middle cut piece of fillet so the beef is an even thickness and cooks evenly.