Let the steaks sit at room temperature for 15-20 minutes. Sprinkle both sides of the steaks with the steak seasoning.
Grill over direct high heat until desired doneness is reached, approximately 8-10 minutes for medium rare. Remove steaks from the grill and allow to rest five minutes.
Using a sharp knife, butterfly the steak from the outer edge along the center forming a pocket. Fill the pocket with the andouille stuffing allowing some to spill out onto the plate.
Melt the bacon fat in a large sauté pan over high heat. Brown the andouille sausage and drain most of the excess fat.
Lower heat to medium and add the onion, red and green peppers and garlic and cook 6-7 minutes more. Add the crushed red pepper flakes and demi-glace.
Bring the mixture to a simmer. Begin adding the butter cubes, a few at a time, stirring constantly with a wire whisk.
Once all the butter has been incorporated, add the salt and remove the stuffing from the heat.
Hold in a warm place until ready to fill steaks.
Yield: 6 servings