1 2-pound beef tenderloin, trimmed
1 tablespoon ground black pepper

For the marinade:
1 medium yellow onion, finely chopped (about 1 cup)
2 cups sliced mushrooms
1/4 teaspoon dried tarragon
1/8 teaspoon salt

To prepare stuffing, spray a large skillet with cooking spray. Add onion to prepared skillet; cook, stirring frequently, until golden about 5 minutes. Add mushrooms, tarragon, and salt; cook, stirring frequently, about 5 more minutes. Remove from heat.

Preheat oven to 350 F. Make a cut, about 2 inches deep, down the long side of the tenderloin. Spread tenderloin open.

Spoon stuffing inside the tenderloin to within 1/2 inch of edges. Roll up tenderloin lengthwise; sprinkle with pepper. Wrap tenderloin in cheesecloth; tie at intervals with string to secure.

Place tenderloin, seam-side down, on a rack in a roasting pan. Roast tenderloin until an instant-read meat thermometer inserted in center reads 160 F. for medium, about 50 minutes.

Place tenderloin on a carving board; let stand for 5 minutes. Remove string and cheesecloth. Slice meat and arrange slices on a serving platter. Serve immediately.

Serves 8