1) Lightly oil the bottom of a large dutch oven, to prevent the nachos from sticking. 2) For the first layer, evenly spread ⅓ of the chips into the dutch oven, topped with ¼ can hot tomato sauce, ¼ can black beans, ¼ cup cheese, and a handful of avocado, green onions, and cilantro. Repeat for the second layer.
3) For the third and final layer, use the remaining ⅓ portion of chips, ½ can hot tomato sauce, ½ can black beans, ½ cup cheese, and the remaining avocado, onion, and cilantro.
4) Cover the dutch oven and place on a metal grill over your campfire for about 10 minutes, until the cheese has melted. Serve with the lime wedges.