I use baked beans. Put your baked beans in the refrigerator for overnight so that they "dry out" slightly. The beans will stick together by morning.
Slice off a "slab" of the beans, throw them on top of some butter in the frying pan until they start to darken up.
Butter the toasted bun, add your cheese, the slab of beans, your burger..you have a burger that will stick to your ribs and is very, very tasty.
A regular at this house.