1.) Mash the cooked black beans with a potato masher or a fork. Add the onions, peppers, egg, and bread crumbs along with the salt, pepper, and any other spices you would like in the burger.
2.) Use your hands to mix all of the ingredients together and form the mixture into two balls of equal size. Using plastic wrap, press each ball in-between two pieces of plastic wrap and form into a patty. Place the patties in the freezer.
3.) Take the carrots and zucchini and toss them in olive oil, salt, pepper, and cilantro if you have it.
4.) Heat the grill to 400 and place the veggies on the hottest part of the grill and cook on both sides for two minutes a piece. Move immediately to the top rack on the cooler part of the grill to continue cooking the veggies without burning them.
5.) Add the onion slice to the grill with the other veggies at this point.
6.) Take the patties and spray the grill with non stick spray and place them directly on the grill. *If your burgers are thin, you may want to cook them on foil to prevent them from going in between the grill grates.
7.) Cook 4 minutes on each side and move to foil under the veggies to continue to cook. *Be careful flipping the burgers as they can fall apart easily.
8.) Once the veggies are tender, place the cheese on the burgers and turn off the heat and after two minutes, place the burger on the lettuce, onion, and tomato and enjoy.