In a large bowl, mash the drained black beans. Add the sautéed onions, crumbled bread, and spices. Mix thoroughly. Add 1/4 cup of cracker crumbs (or just enough to be able to form patties from the mixture). Form the mixture into 1/2-inch thick patties. Gently coat each patty with more cracker crumbs. Heat oil in non-stick pan over medium heat. Fry both sides of the patties.

Serve with a garnish of lettuce, tomatoes, avocado, and any other condiments on buns or over a bed or rice.