Preheat your oven to 400°F (200°C).

Pat the filet mignon steaks dry with paper towels. This will help achieve a nice sear.

Rub each steak with olive oil and season generously with blackening seasoning, salt, and pepper on both sides.

Heat a cast-iron skillet over high heat until it begins to smoke lightly.

Carefully place the seasoned steaks in the skillet and sear for about 3-4 minutes on each side until a dark crust forms.

After searing, transfer the skillet to the preheated oven and cook for an additional 5-7 minutes for medium-rare, or until your desired doneness is reached.

While the steaks are cooking, prepare the coarse Dijon-mustard butter. In a small bowl, combine the softened butter, coarse Dijon mustard, chopped tarragon, minced garlic, and a pinch of salt. Mix until well combined.

Once the steaks are done, remove them from the oven and let them rest for about 5 minutes.

Serve the filet mignon topped with a generous dollop of the coarse Dijon-mustard butter.

Enjoy your Blackened Garlic and Tarragon-Crusted Filet Mignon!