In a mixing bowl, combine the tomatoes, onion, bell pepper, lime juice, cilantro, and salt. Mix to combine. Cover and set aside to rest.
Meanwhile, in a small bot, heat the black beans and vegetable broth, bring to a simmer and cook for about 5 minutes. Remove from heat and lightly mash making sure to leave some beans whole and the mixture very chunky.
Heat a large skillet on high heat, an iron fry pan works great! When the pan is very hot, add one corn tortilla. Cook for about 30 seconds, or until browned and turn over to cook the second side for about 30 seconds. Place the browned tortilla on a warm plate. Repeat with remaining tortillas.
Place the tortillas on a flat surface and spread with the black beans. Top the beans with mango and avocado. Spoon the tomato mixture on top. Serve and enjoy!