1. In a skillet, heat 1 tablespoon of olive oil over medium heat. Add the chopped onions and garlic, and sauté until softened.
2. Add the chopped mushrooms to the skillet and cook until they release their moisture and become tender. Remove from heat and let cool.
3. In a mixing bowl, combine the mashed black beans, breadcrumbs, soy sauce, cumin, paprika, salt, and pepper. Add the cooled mushroom mixture and mix well.
4. Form the mixture into 4 equal-sized patties.
5. Heat the remaining olive oil in the skillet over medium heat. Cook the patties for about 4-5 minutes on each side, or until they are golden brown and heated through.
6. Serve the mushroom veggie burgers on buns with your favorite toppings.