Preheat the grill. In a bowl, mix the meat. Form 4 (3-ounce) patties by using a scoop. Push them down and make little indentations in the middle to hold the flavors. Place a chunk of mozzarella and drizzle some chili paste or chili flakes on top of the mozzarella. Add a good twist of black pepper. Take another 3-ounce scoop of meat, make it flat in your hand and place right on top of the other half.
Take your fingers and just seal the 2 patties up and refrigerate until you are ready to grill.
Meanwhile: Split the pieces of bread, and pull out some of the soft center to make a hole for the burger. Place the bread face down on the grill to toast.
Place the burger in the bread, and top with your favorite condiments.
Recipe courtesy of Michael Chiarello