Prepare the garlic cheese bread by following the instructions on the packaging, and let it cool.
In a pan, heat some olive oil over medium heat and cook the bell peppers and onions until they are tender. Once done, remove from heat and set aside.
Cook the shaved cheesesteak meat in a pan until it is browned, then set aside.
Place one slice of provolone cheese on three pieces of the cooled garlic cheese bread.
Add the cooked cheesesteak meat, onions, and bell peppers on top of the cheese.
Cover each sandwich with a slice of mozzarella cheese and another piece of garlic cheese bread.
In a separate pan, melt some butter over medium heat.
Place the sandwiches into the pan and cook for several minutes on both sides until the bread is toasted and the cheese has melted.