If the beans are frozen, partly defrost by opening the plastic bag about inches to vent and micro- waving them on high, for about 3 minutes. Meanwhile, place the broth and sugar in a 4 1/2 quart Dutch oven or soup pot over high heat, cover the pot and bring it to a boil. Remove the beans from the bag, add them to the pot, and stir gently to break up any frozen chunks of beans. Do not mash the beans. When the soup returns to a boil, reduce the heat to medium low. Stir in the lime juice. Crush the chips slightly and place in soup bowls. Ladle the soup over the chips, sprinkle with cheese. Serve at once. Makes 5 servings