Cut flour tortillas into large squares and then divide each into quarters, making 4 smaller equally sized square pieces, per flour tortilla.
Preheat oven to 350ºF (180ºC).
Generously coat a standard-size muffin tin with nonstick cooking spray.
Line each cup of prepared muffin tin with a tortilla sheet.
Spoon a tablespoon of refried beans into each sheet.
Sprinkle shredded cheese over each sheet.
Place another sheet on top of the bean/cheese mixture and press so it flattens.
Bake for 15 minutes.
Spoon in a tablespoon of guacamole, sour cream, and salsa into each cup then top with green onions and tomato.
