Filet Mignon Recipe

1. Prep and season

Bring the 10 oz filet to room temperature for 30–45 minutes. Pat dry with paper towels. In a small bowl, combine porcini mushroom powder, kosher salt, and black pepper. Rub the porcini-salt-pepper evenly over all sides of the steak.

2. Sear and grill

Heat a heavy cast-iron skillet or grill pan over high heat until smoking. Add neutral oil and swirl. Sear the filet 2 minutes per side to develop a brown crust. Reduce heat to medium-high, add 1 tablespoon butter, and baste the steak for 1 minute while spooning melted butter over the top. Continue cooking until an instant-read thermometer reads 125°F for medium-rare (approximately 6–8 minutes total depending on thickness) or adjust to desired doneness. Remove to a cutting board and tent loosely with foil; rest for 6–8 minutes.

3. Finish

After resting, transfer the filet to a warm plate. Reserve any pan juices to incorporate into the Chasseur sauce if desired.

4. While the steak rests, make the sauce. In the same skillet used for the steak (discard excess fat leaving about 1 tablespoon), add 2 tablespoons butter over medium heat. Add the minced shallot and cook 1–2 minutes until translucent. Add the minced garlic and sliced mushrooms and sauté until mushrooms release liquid and are browned, about 4 minutes.

5. Deglaze the pan with 1 tablespoon white wine, scraping up browned bits. Allow the wine to reduce by half (about 1 minute). Stir in the chicken or beef stock and the tomato concassé; simmer 2–3 minutes to reduce slightly.

6. Whisk in Dijon mustard and heavy cream, simmer gently until sauce coats the back of a spoon, about 2 minutes. Stir in chopped tarragon or parsley, season with salt and black pepper to taste. If you reserved pan juices from the steak, whisk a teaspoon or two into the sauce for extra flavor. Keep warm until serving.

7. Preheat oven to 375°F (190°C). Rub a small gratin dish or ovenproof skillet with the halved garlic clove, then coat with 1 tablespoon butter.

8. Arrange a layer of very thinly sliced potatoes in the dish, slightly overlapping. Season lightly with a pinch of salt and pepper and a tiny dusting of nutmeg. Sprinkle a little Gruyère and Parmesan over the layer. Repeat layering until potatoes are used, finishing with cheese on top.

9. Combine 1 cup heavy cream and 1/2 cup whole milk in a measuring cup; warm slightly (do not boil). Pour cream mixture over the potatoes so it comes about three-quarters up the sides. Cover tightly with foil and bake for 35 minutes. Remove foil and bake uncovered 15–20 minutes more until top is golden and potatoes are tender when pierced with a skewer.

10. Let the gratin rest 5 minutes before serving. Cut into a portion to serve alongside the filet.

11. While gratin bakes and steak rests, preheat oven to 425°F (220°C) or prepare a hot skillet. Toss trimmed asparagus with olive oil, salt, and pepper.

12. Roast on a sheet pan for 8–10 minutes until tender-crisp and lightly charred, or sauté in a hot skillet 4–6 minutes, shaking pans occasionally. Finish with a squeeze of lemon just before serving if using.