Preheat oven at 400. Prepare a 8 square dish with cooking spray; set aside.
In a large saucepan, cook chicken, onions, bell peppers, and garlic until chicken is no longer pink.
Stir in taco seasoning mix and taco sauce; set aside.
In a medium sized bowl, combine sour cream and cottage cheese; set aside.
Place half the crushed chips onto the bottom of the prepared dish. Add chicken mixture to cover the chips, then cover the chicken mixture with sour cream mixture.
Sprinkle with cheese and remaining crushed chips.
Bake, uncovered, for 30 minutes or until cheese has melted.