Filet Mignon with Mustard Butter

Ingredients

• 4 tablespoons unsalted butter, at room temperature
• 2 teaspoons Dijon mustard
• 2 teaspoons grain mustard
• 8 1/4-pound tenderloin medallions, room temperature
• Vegetable oil
• Kosher salt
• Freshly cracked black pepper

Directions

1. Stir the softened butter with both mustards in a bowl until evenly combined. Shape the mixture into a log about two inches long, wrap it in plastic wrap, and chill until firm, about 1 hour.
2. Remove the butter from the refrigerator. Heat a cast iron skillet over high heat. Add just a light drizzle of vegetable oil to the meat, then rub it over each piece so the medallions are thinly and evenly coated. Season every side generously with salt and pepper.
3. Set the medallions in the hot cast iron pan, working in two batches if your skillet needs the space. Cook until the first side develops a deep brown crust, about 8 minutes. Flip the medallions and continue cooking until the internal temperature just reaches 130 degrees F, about another 4 to 5 minutes.
4. Transfer the medallions to a serving platter. Cut the mustard butter log into 8 coins, then set one coin on each hot steak so it melts as the meat rests. Serve immediately, with some baguette or plain steamed potatoes to catch the extra butter and juices.