I use left over bread or hamburger buns,a good way to use bread up if it has gone a bit stale.
If using bread just cut the crust off and cut the bread into two slices,I place the cut slices into a small baking dish and spread with some crushed garlic,sweet chilli sauce and top with grated cheese,the just place it in a hot oven until browned.
You can omit the sweet chilli sauce if you want.
If using buns just break them in half and do the same thing.