Combine the mango, shallot, pepper, cilantro, lime juice and a big pinch of salt and pepper in a bowl. Toss well. You can make this a few hours ahead of time and store it in the fridge if needed.
In a bowl, toss the black beans with salt, pepper, paprika, cumin and garlic. Use a fork to mash and smash some of the beans coarsely. You also want some whole beans!
Heat a nonstick skillet over medium heat. Add the black beans and cook, tossing once or twice, until the edges are crisp and everything is warm. Sprinkle on a little bit of the cheese and let it melt.
Transfer the beans to a plate.
To make the tacos, use the same skillet. Add a drop of olive oil or butter. On one side of each tortilla, sprinkle on some cheese and add some beans. Fold the tortilla over and cook it in the hot skillet, until both sides are golden and crisp and all the cheese is melted.
Serve with the mango salsa!