Preheat the oven to 350 degrees F.
Heat the olive oil in a skillet over medium heat and add the onion, garlic and jalapeno.
Stir while cooking for 5 minutes, then add the cumin and stir.
Transfer to a blender with the chiles, salt and pepper and blend.
Heat the tortillas in a small amount of olive oil in a skillet to soften, then dip into the enchilada sauce and place onto the baking dish.
Fill each tortilla with black beans and a little cheese, then roll up.
Top the enchiladas with the rest of the sauce, then cheese and tomatoes.
Bake for 30 minutes, until cheese is melted and starting to brown slightly.
