Slow Roasted Beef Tenderloin with Horseradish-Mustard Sauce
Author:By Lee Clayton Roper
Yield:6 servings 1x
Category:Beef, Entertaining, Gluten free
1 (2 1/2 to 3-pound) whole beef tenderloin, trimmed and tied*
Fresh ground pepper
3/4 cup mayonnaise
1/4 cup prepared horseradish (or more to taste)
2 tablespoons sour cream
1 tablespoon whole grain or creole mustard
2 teaspoons Dijon mustard
Kosher salt, to taste
Preheat the oven to 275 degrees.
Pat the tenderloin dry with paper towel. Brush all over lightly with olive oil. Season generously with salt and fresh ground pepper. Let sit at room temperature for 20 to 30 minutes.
Coat a skillet (preferably cast iron) large enough to hold the tenderloin with vegetable oil and heat over high heat – or heat a grill to high. When hot, sear the outside of the tenderloin just until browned on all sides. Don’t turn too much!
Place the seared tenderloin in a roasting pan or on a broiler rack and roast until the internal temperature reaches 135 degrees for medium rare or 145 degrees for medium – around 45 to 60 minutes. I recommend checking the temperature frequently, starting at around 30 minutes. the size and thickness of your tenderloin can change the cooking time significantly
When meat reached desired temperature, remove it from the oven, cover with foil and let sit for at least 10 minutes before serving.
For the horseradish-mustard sauce: in a medium mixing bowl, stir all ingredients together. Cover and refrigerate for at least 30 minutes to allow the flavors to blend. Season to taste with kosher salt before serving.
*Ask your butcher to trim and tie the tenderloin for you.
Make ahead: The sauce can be prepared, covered and stored in the refrigerator up to 2 days before serving. The tenderloin can be seared, roasted, cooled, covered, and refrigerated earlier in the day. Bring to room temperature before serving.