Tia Talana's Mexican Pizza Casserole

1 1/2 lb hamburger
1 large onion
1 can green chiles (7 oz.)
2 cans cream of chicken soup
3-4 c. shredded cheese
6-9 tortillas

Brown hamburger and onion. Add chiles and soup. Layer 1/3 of torn tortillas, 1/3 of meat mixture and 1/3 of cheese in 9x13 in. baking pan. Repeat two more times until all ingredients are used up. Bake at 350* for 30 minutes until bubbly and cheese is melted.