1. Heat oven to 350 degrees F. Put the chips in a baking dish.
2. In a small saucepan, combine the black beans and salsa and heat on medium. Spoon some of the mixture into the center of each chip.
3. Sprinkle on cheese. Then pop the chips into the oven for about 5 minutes, or until the cheese melts. Put the nachos on a plate, and add a dollop of sour cream.