- 2 tablespoon butter
- 1/4 cup chopped shallots or yellow onion
- 1 cup chopped fresh mushrooms
- 1 (1 1/2-pound) beef tenderloin
- Salt and freshly ground black pepper
- Soy sauce, to taste
Preheat oven to 400 degrees F.
In a medium skillet, melt the butter and cook the shallots or onion over low heat until tender, about 5 minutes. Add the mushrooms and cook over low heat about 5 minutes or until the liquid is reduced by half. Let cool.
To stuff the tenderloin, open the beef and sprinkle in the inside with salt and pepper and rub with soy sauce. Spoon the mushroom mixture down the center of the tenderloin. Bring the 2 sides of the tenderloin up and around the filling to meet. Using butcher string, tie the tenderloin together at 2-inch intervals. Place the tenderloin in a roasting pan.
Roast for 40 minutes for medium rare. Let stand for 10 minutes before slicing. Slice about 1 1/2 inches thick.