Take the steaks or chicken out of the marinade (reserve marinade) and grill on the barbeque until done. While you are grilling, put the reserved marinade into a heavy sauce pan and cook on medium heat, stirring constantly so it does not burn. Cook for approximately 15 minutes or until liquid starts to thicken. Add 2 tablespoons corn starch and 1/4 cup water to sauce and stir constantly until thick. Pour a small amount of sauce over grilled steaks or chicken and serve remaining sauce in a gravy dish.