Perfect Roast Tenderloin of Beef with Horseradish Sauce

Serve this succulent dish — enhanced by a creamy sauce with just a bit of tang — for seated dinners or festive buffets. Yield: 10 to 12 servings For the Roast Tenderloin 1 6- to 8-pound beef tenderloin, trimmed 2 teaspoons salt 1 teaspoon ground black pepper 2 tablespoons dried thyme 1 stick (8 …