Tostada Casserole

Directions

1. 1
   Coarsely break taco shells.
2. 2
   In a 2-quart bowl, mix beef and onion.
3. 3
   Cover bowl with waxed paper.
4. 4
   Cook at High for 4 to 5 minutes, stirring and breaking up meat into small pieces every 2 minutes.
5. 5
   Tilt bowl, skim and discard excess fat.
6. 6
   Stir in tomato sauce, water and chili powder.
7. 7
   Cover.
8. 8
   Cook at High for 4 minutes or until meat mixture thickens, stirring after 2 minutes. Stir in undrained green chilies and shredded cheese.