Cook ground chicken in deep frying pan until golden brown. Add chili powder.
Add salsa, green peppers, jalapenos, and black beans to chicken in frying pan. Simmer for about 5 minutes or until heated thoroughly.
Place half the chicken mixture into a 8x8" baking dish (preferably round). Layer 1/2 cup of cheese on top, one tortilla shell, another tortilla shell, remaining chicken mixture, 1/2 cup of cheese, sour cream, 1 cup of cheese.
Place in oven at 350 °F (175 °C) until cheese has melted (about 20 minutes).
Add chopped tomatoes and lettuce. Serve!
There are 638 calories in 1 serving of Chicken Taco Casserole.