Season the flap steak with oil, salt and black pepper thoroughly.
Using Cowboy Charcoal, fill a full chimney of coals, light and let preheat for 15 minutes. Pour coals into grill and place into one pile for 2-zone cooking.
Lay the flap steak directly over the hot Cowboy Charcoal, and let sear both sides for 1-2 minutes to create a crust. Pull steak away from coals and step for indirect cooking. Lather the marinara, mozzarella cheese, pepperoni, olives and any other toppings you desire. Close lid and let cook for 10 minutes or until the steak is 120F and the cheese has melted.
Once done, pull steak off grill and let rest for 10-12 minutes.
Top steak with red pepper flakes, chopped basil and salt. Slice against the grain and enjoy!