Take the fillet mignon out of the refrigerator and remove it from its packaging at least 20 minutes (ideally 1 hour) before you want to cook it.

Pat the filets dry with a paper towel and place on a plate. Sprinkle both sides with sea salt, black pepper, and garlic powder and allow it to sit in its seasoning while it comes to room temperature.

Add 2 to 3 tablespoons to a well-seasoned cast iron skillet and heat to medium-high. You want enough oil to generously coat the surface of the cast iron. Allow the cast iron to heat for a few minutes - ideally to 375 to 385 degrees F (you can take the temperature with a laser thermometer).

Carefully place the fillet mignon on the hot skillet and sear for 3 to 5 minutes per side, depending on your desired level of done-ness. Use a thermometer to check the internal temperature. For Medium rare: 130-135° , Medium: 135-145° , Medium well: 145-155°

Immediately transfer the fillets to a plate and allow them to sit untouched for at least 15 minutes before serving. This process is crucial for the optimal tenderness of the meat.

Note: If your filet mignon is very thick (3 inches thick or more), finish cooking it in the oven at 400 degrees F, until it reaches your desired level of done=ness. This will prevent the outside of the filets from burning while achieving a perfect result on the inside.