PREHEAT OVEN TO 350 DEGREES.
IN A LARGE SKILLET, COOK THE GROUND BEEF AND ONION UNTIL THE BEEF IS NO LONGER PINK AND DRAIN.
ADD THE TACO SEASONING AND REFRIED BEANS AND HEAT THROUGH.
IN A SEPARATE BOWL, BLEND THE MUSHROOM SOUP WITH THE SOUR CREAM. THEN SPREAD HALF OF THE SOUP MIXTURE IN THE BOTTOM OF A BAKING DISH.
ADD A LAYER OF 3 FLOUR TORTILLAS TO THE TOP OF THE SOUP MIXTURE. YOU WILL NEED TO CUT OR TEAR THE TORTILLAS AND OVERLAP THEM.
SPREAD ON A LAYER OF THE GROUND BEEF MIXTURE AND TOP WITH ABOUT A CUP OF CHEESE.
REPEAT ALL OF THESE LAYERS AND TOP WITH THE REMAINING CHEESE.
BAKE FOR ABOUT 20 MINUTES UNTIL CHEESE IS NICELY MELTED. ENJOY!