This is for a 3 pound that would feed 4-6 but maybe you could enlarge the recipe.
1-3pound tenderoin
2 tablespoons butter
1/2 pound fresh mushrooms, sliced
1 clove garlic, crushed
2 tablespoons roquefort cheese
1 teaspoons salt
1/4 teaspoon pepper
Cut pocket in meat. Saute mushrooms in one tablespon butter for 2 minutes. combine mushrooms, cheese, remaining 1 tablespoon butter, garlic, 1/2 teaspoon salt and 1/8 teaspoon pepper. Stuff pocket with mixture. Fasten with skewers or tie. Sprinkle with the remaining salt and pepper. roast at 325 degrees until meat thermometer register 165 degrees about 2 hours..

This is not stuffed but we really like it better than the stuffed version.

1-3 pound tenderloin
salt and pepper
mushroom-wine sauce
meat drippings
1 medium onion, thinly sliced and separated into rings
1/2 cup dry red wine
2 tablespoons cornstarch
1/4 teaspoon pepper
1 cup beef broth
1 4.5 ounce jar drained and sliced mushrooms
2 tablespoons fresh parsely, chopped

Heat oven to 325 degrees. Rub meat with salt and pepper; place on rack in shalow roasting pan. Insert meat thermometer in center of meat. roast at 325 degrees until 165 degrees. When meat is done, remove from oven and let stand for 15 minutes while preparing sauce. Sauce: Spoon meat drippings into medium skillet. Add onion; cook over medium heat until tender. Add wine and bring to a boil. In a small bowl, combine cornstach, 1/4 teaspoon pepper and beef broth; slowly add to onion mix, stirring constantly. Cook until thickened, stirring constantly. Stir in mushroms and parsley; heat thoroughly. To serve, slice roast; serve with sauce. 4-6 servings.