Beef tenderloin cooks up alot like filet mignon, so it doesn't require hours of cooking to be tender. Here's a recipe I've enjoyed on special occasions:
2 beef tenderloins, butterflied
1 cup button mushrooms, sliced
1/2 yellow onion, finely chopped
1/2 cup finely chopped carrots
1 Tsp fresh thyme
2 cloves finely chopped garlic
1/2 cup red wine
1 T kosher salt, divided in half
1 Tsp fresh ground pepper
1 cup coarse bread crumbs
3 T butter
Saute mushrooms, onion, garlic,and carrots in butter until tender and translucent. Add 1/2 of the salt, pepper, and red wine. Reduce heat, cover and simmer for 15 minutes. Remove from heat and stir in breadcrumbs. Mixture should be moist but not "goopy". Add more breadcrumbs if it is too damp. Sprinkle inside and outside with remaining salt and pepper. Spoon stuffing into center of each filet and roll up. Secure with bakers twine and place in baking dish. Cover with foil and place in 375 degree oven. Cook until internal temperature reaches 150 degrees. Remove from oven and create "tent" with foil. Let "rest" for 15 minutes. Meat will continue to cook while it sits. In the meantime, in large skillet heat:
2 T butter
1 T dijon mustard
1 cup cabernet sauvignon
1/2 tsp kosher salt
Fresh ground pepper
Bring to a boil and boil until reduced and thickened. Adjust seasonings to taste and spoon over sliced beef tenderloin.