Roast Beef Tenderloin with Creamy Mushroom Sauce

Step 1: Pat the beef dry with paper towels and sprinkle it all over with the salt and pepper. Set it on a rack over a tray and refrigerate uncovered for 12 to 24 hours. You can skip this step if needed.

Step 2: Mix the garlic-thyme butter ingredients together in a bowl.

Step 3: Remove the beef from the refrigerator 2 hours before cooking to take off some of the chill and help it cook evenly.

Step 4: Heat the oil in an ovenproof heavy-based pan over high heat until smoking. Quickly brown the beef all over, searing the surface aggressively. Return it to the rack and let it cool for 15 minutes so the butter will not melt immediately when applied.

Step 5: Preheat the oven to 120°C/250°F.

Tip: This temperature applies to both fan and standard ovens.

Step 6: Return the beef to the cooled skillet. Spread three-quarters of the butter over the top and sides, not the underside.

Step 7: Roast for 15 minutes. Remove the pan and spread the remaining butter over the top and sides. Roast for a further 25 to 35 minutes, for 40 to 50 minutes total, or until the internal temperature reaches 53°C/127°F for medium rare.

Tip: For other levels of doneness, use the temperature guidance in the recipe notes.

Step 8: Transfer the beef from the skillet to a cutting board and rest for 10 minutes. For medium rare, the internal temperature will rise to 56–58°C/133–136°F. Slice thickly and serve with the creamy mushroom sauce.

Step 9: Pour the skillet juices into a bowl or jug and let the fat rise to the surface. Pour 1/4 cup (60 ml) of the fat back into the skillet and reserve the rest for later.

Step 10: Turn the stovetop to high. When the butter is hot, add the mushrooms and cook until they start to sweat. Add the thyme and garlic, then cook for a further 2 minutes, until the mushrooms are softened.

Step 11: Add the chicken stock and reduce it by half. Add the Marsala, cream, pepper, and the remaining reserved roasting juices. Simmer over medium to medium-high heat for 5 minutes, until the sauce reduces by half and thickens. Taste; it should be slightly on the salty side. Add more salt if needed, then serve with the beef.