Preheat oven to 375 degrees.
Heat butter in a large skillet over medium high heat.
Saute chopped onions and green chilies for about 2-3 minutes or until onions are tender. Turn off heat.
Add in half of the black beans and smash using a wooden spoon or spatula.
Stir in remaining beans and 1 cup of cheese.
Pour ¾ cup of enchilada sauce into the bottom of a 9x13 pan and spread evenly.
Fill each tortilla with about ¼ cup of filling and roll up.
Place seam side down into the pan. Scoot them to all fit.
Pour remaining enchilada sauce over the top evenly and top with remaining cheese.
Cover with foil and bake for 30 minutes.
Uncover and bake an additional 5 minutes or until cheese is completely melted and bubbly.
Cool for 10 minutes and garnish with jalapeno slices, queso fresco, tomatoes and cilantro.