Preparation Steps:

• Start by removing the filet mignon steaks from the refrigerator about 30 minutes before cooking. This allows them to come to room temperature, ensuring even cooking. Pat the steaks dry with paper towels to remove any moisture.
• In a mixing bowl, combine the olive oil, kosher salt, and black pepper. Rub this mixture all over the steaks, ensuring they are well-coated.
• Preheat your air fryer to 400°F (200°C) for about 5 minutes. Preheating is crucial as it helps sear the steak immediately, locking in juices.
• Place the seasoned filet mignon steaks in the air fryer basket in a single layer. Cook for 10-12 minutes for medium-rare, flipping halfway through the cooking time. Use a meat thermometer to check for doneness; it should read 130°F (54°C) for medium-rare.
• Once the steaks are cooked to your liking, remove them from the air fryer. Spread softened butter generously on top of each steak while they rest for about 5 minutes.
• Slice the filet mignon against the grain and serve it on a plate. Garnish with fresh rosemary for a pop of color and flavor.