Ingredients

1/3 cup dried porcini mushrooms
1 cup warm water
2 1/2 pounds trimmed beef tenderloin roast, tied
Salt and ground black pepper to taste
1 tablespoon vegetable oil
1 tablespoon unsalted butter
1/2 cup sliced shallots
1 pinch salt
1/4 tarragon vinegar
1 cup veal or chicken stock
1/4 cup heavy cream

1 tablespoon unsalted butter
1 table chopped fresh tarragon
Salt and ground black pepper to taste

Directions
1. Combine porcini mushrooms and water in a bowl; soak until soft, 1 hour. Drain and reserve liquid. Dice mushrooms and reserved liquid aside.
2. Preheat oven to 345 degrees F.
3. Season beef generously with salt and pepper. Heat vegetable oil in a large ovenproof skillet over high heat. Place beef in the skill; cook until brown on all sides, 5 to 8 minutes per side.
4. Reduce heat to heat to medium and stir in 1 tablespoon butter, shallots, and a pinch of salt; cook until shallots are soft and translucent, 5 to 7 minutes.
5. Pour tarragon vinegar into the skillet and bring to a boil while scraping any browned bits off of the bottom. Stir until liquid is reduced by half, 2 to 4 minutes.
6. Pour in veal or chicken stock, cream, 1/2 cup reserved mushroom liquid, mushrooms, salt, and pepper; stir to combine. Return beef to the skillet.
7. Roast in the preheated oven until meat is medium rare, about 45 minutes. An instant-read thermometer inserted into the center should read 130 degrees F. Transfer meat to a plate and loosely tent with foil. Set skillet over high heat and bring pan juices to a boil.
8. Stir in 1 tablespoon butter and tarragon; season with salt and pepper to taste. Return tenderloin and any accumulated juices to skillet and serve.

Find the recipe here, also, a helpful video on how to make it!