Looking for a perfectly cooked filet? Preheat oven to 415 degrees. Put the filet on a plate and sprinkle with rosemary and salt and pepper. Place two tablespoons of butter in the cast iron skillet and sear the filet on med-high heat for two minutes, alternating sides. Immediately transfer to the preheated oven. Cook it for 5-6 minutes for medium rare. Get yourself a side of Bellisari’s Saigon Street Sauce as smear.