Chicken Tortilla Delight

4 chicken breasts, cooked
1 pkg. tortillas, 12
1 onion, cut fine
1 can green chilies (1/3 cup)
1 can cream of chicken soup
1 can cream of mushroom soup
1 c. milk
16 oz. cheddar cheese

Cut up tortillas. Mix with all other ingredients except cheese.  Put in large casserole dish. Top with cheese. Bake at 350º for 1 hour or microwave until heated through.