Steakhous Steak with Sauteed Wild Mushrooms

I saw this filet mignon recipe on Barefoot Contessa and vow to make it.. she also made these onion rings and mushroom dish with it

2 (10-ounce) filet mignon
2 tablespoons vegetable oil
1 tablespoon fleur de sel
1 tablespoon coarsely cracked black peppercorns
2 tablespoons unsalted butter, at room temperature,
optional Roquefort Chive Sauce, recipe follows

Preheat the oven to 400 degrees F.
Heat a large, well-seasoned cast iron skillet over high heat until very hot, 5 to 7 minutes.
Meanwhile, pat the steaks dry with a paper towel and brush them lightly with vegetable oil. Combine the fleur de sel and cracked pepper on a plate and roll the steaks in the mixture, pressing lightly to evenly coat all sides.
When the skillet is ready, add the steaks and sear them evenly on all sides for about 2 minutes per side, for a total of 10 minutes.
Top each steak with a tablespoon of butter, if using, and place the skillet in the oven. Cook the steaks until they reach 120 degrees F for rare or 125 degrees F for medium-rare on an instant-read thermometer. (To test the steaks, insert the thermometer sideways to be sure you're actually testing the middle of the steak.)

Remove the steaks to a serving platter, cover tightly with aluminum foil and allow to rest at room temperature for 10 minutes. Serve hot with Roquefort Chive Sauce on the side.

Roquefort chive sauce:
1 1/2 cups heavy cream
2 ounces French Roquefort cheese, crumbled (4 ounces with rind)
1/2 teaspoon kosher salt
1/4 teaspoon freshly ground black pepper
1 tablespoon chopped fresh chives

Bring the heavy cream to a boil in a small heavy-bottomed saucepan over medium-high heat. Cook at a low boil, stirring occasionally, until the mixture has become thick and creamy, about 20 minutes. Remove the pan from the heat, add the cheese, salt, pepper and chives and whisk rapidly until the cheese melts.
Yield: 4 servings

Sauteed Wild Mushrooms
Prep Time:
25 min
Inactive Prep Time:
hr min
Cook Time:
15 min
Level:
Easy
Serves:
4 servings

Sauteed Wild Mushrooms

2 pounds mixed wild mushrooms, such as cremini, shiitake, porcini, and portobello
1/2 cup good olive oil
1 cup chopped shallots (4 large)
4 tablespoons (1/2 stick) unsalted butter
2 teaspoons kosher salt
1/2 teaspoon freshly ground black pepper
2 tablespoons chopped garlic (6 cloves)
1 cup chopped flat leaf parsley

Brush the caps of each mushroom with a clean sponge. Remove and discard the stems. Slice the small mushrooms thickly and cut the large ones in a large dice.
Heat the olive oil in a large (11 - inch) Dutch oven or saucepan. Add the shallots and cook over low heat for 5 minutes, or until the shallots are translucent. Add the butter, mushrooms, salt, and pepper and cook over medium heat for 8 minutes, until they are tender and begin to release their juices, stirring often. Stir in the garlic and cook for 2 more minutes. Toss in the parsley, sprinkle with salt, and serve warm.