Heat oven to 375°F.
Spray 8 1/2-inch tortilla shell pans with cooking spray. (Use 4 if you have them; otherwise, make as many at a time according to the number of pans you have.) Place 1 tortilla in each pan, and press gently against ridges. Bake about 10 minutes or until golden. Turn pans upside down to release tortilla shells.
While tortilla shells are baking, microwave fiesta rice as directed on package.
Place equal amounts of rice, black beans and refried beans into each tortilla shell. Divide avocado slices among tortilla shells, and top each with 1/4 cup cheese.