In a clean skillet, add 1 tablespoon of oil. Sauté onion, garlic, and 1/2 cup mushrooms, over medium-high heat, for about 4-5 minutes or until the mushrooms are slightly browned. Transfer and let cool.
In the same pan, sauté the rest of the mushrooms. Transfer to a plate and set aside. You will use these to top the burgers.
In a food processor, add mushroom mixture, black beans, egg, cumin, oregano, paprika, Worcestershire sauce, bread crumbs, salt and pepper. Mix until everything is combined. Shape the mixture into patties.
In the same skillet, add the remaining tablespoon of olive oil. Cook patties, over medium heat, for about 5 minutes on each side until heated through. Melt cheese slices on top of each patty.
Place each patty over one plantain, add sautéed mushrooms on each patty then top with another plantain. Serve and enjoy!