If you are using sprouted garbanzos, steam them until just tender, about 10 minutes.Most of you will be using canned beans, so jump right in and combine the garbanzos, eggs, and salt in a food processor. Puree until the mixture is the consistency of a very thick, slightly chunky hummus. Pour into a mixing bowl and stir in the cilantro, onion, zest, and sprouts.Add the breadcrumbs, stir, and let sit for a couple of minutes so the crumbs can absorb some of the moisture. The mixture should be moist enough to easily form and hold a patty shape. Add more bread crumbs a bit at a time to firm up the dough if need be. Conversely, a bit of water or more egg can be used to moisten the batter. Form mixture into 12 patties.Heat the oil in a heavy skillet over medium low, add 4 patties, cover, and cook for 7 to 10 minutes, until the bottoms begin to brown. Turn up the heat if there is no browning after 10 minutes. Flip the patties and cook the second side for 7 minutes, or until golden. Remove from the skillet and cool on a wire rack while you cook the remaining patties. Serve on buns topped with avocado, tomato, onion, and more sprouts, if desired. Alternatively, you can make extra-thick patties (1 1/2 inches), and slice them in half after cooking. Put the filling inside the patty, and you have a self-bunning-burger.