From the cookbook Mug Meals by Dina Cheney.
Spray the inside of a 12-oz. mug with cooking spray.
In a small bowl, stir together the beans and salsa.
Place half of the chips in the mug and top with a third of the cheese and half of the bean-salsa mixture. Top with the remaining chips, another third of the cheese, and the remaining bean mixture. Top with the remaining cheese.
Cover and microwave until most of the cheese melts, about 1 minute. Uncover and microwave until the remainder of the cheese melts, about another 30 seconds. Top with the avocado and other garnishes, and serve with additional chips, if desired.