Roast Beef Tenderloin with Horseradish

Ingredients

• 1.8 kg (4 lb) whole center-cut beef tenderloin, trimmed and tied at 4 cm (1½ in) intervals
• 1 tbsp coarse salt
• 1 tsp black pepper
• 2 tbsp olive oil
• 4 sprigs thyme
• 1 tbsp butter

Horseradish cream

• 180 ml (¾ cup) sour cream
• 3 tbsp prepared horseradish, drained
• 1 tbsp Dijon mustard
• 1 tsp lemon juice, plus ½ tsp finely grated zest
• 1 tbsp chopped chives
• Salt and pepper

Steps

1. Pat the tenderloin dry. Rub it all over with the salt and pepper and leave it uncovered at room temperature for 1 hour. If the thin tail end is much narrower, tuck it under and tie it so the roast is an even thickness.
2. Heat the oven to 230°C (450°F) with a rack in the middle. Stir the horseradish cream ingredients together, taste, and chill.
3. Heat the oil in a large heavy skillet over high heat until almost smoking. Sear the tenderloin for 2 minutes per side, turning until browned all over, about 8 minutes in all.
4. Lay the thyme on a roasting pan, set the roast on top and dot with the butter.
5. Roast for 20 minutes, then start checking. Pull it out when a thermometer in the thickest part reads 49–52°C (120–125°F) for medium-rare, usually 25–35 minutes in total.
6. Tent loosely with foil and rest for 15 minutes; the temperature will rise by about 5°C (10°F).
7. Remove the strings and cut into slices 1.5 cm (½ in) thick. Serve with the horseradish cream.

Notes

• Make ahead: sear the roast up to 4 hours ahead, refrigerate it, then bring to room temperature and roast. The horseradish cream improves overnight.
• Cold leftovers: thin slices make superb sandwiches with the sauce; keep them 3–4 days in the fridge.
• Buying: ask your butcher to trim the silverskin and chain; it is the tough membrane that will not melt in cooking.
• Chef's touch: lemon zest in the cream adds fragrance without extra sharpness.
• Pair with: roasted asparagus or green beans and crisp roast potatoes.