In a large pot, cook bell peppers, garlic, and onions in a small amount of the fat of your choice until they begin to sweat. Add ground meats and cook until browned. (If you don’t have ground heart or liver, just substitute ground beef. Whatever you do, don’t add more liver if you don’t have enough heart! The flavor will become too noticeable and take over the happy pizza experience you’re creating.)
Stir in olives, optional pepperoni, marinara sauce, and water. Bring to a boil. Add salt, basil, and red pepper flakes to taste. Allow flavors to mingle over medium heat for 5-10 minutes.
Reduce heat and serve in bowls, topped with optional mozzarella cheese.