Preheat oven to 350 and grease a 9x13 baking dish with nonstick cooking spray. Set aside.
Add butter, uncooked chicken pieces, and diced onion to a large skillet and cook over medium-high heat until the onions are translucent and the chicken is no longer pink.
Stir in rinsed black beans, drained whole-kernel corn, cream of chicken soup, chilies, and pieces of cream cheese.
Cook chicken mixture over medium-low heat until the cream cheese is melted and the mixture is smooth.
Place 1/3 of the Frito corn chips onto the bottom of the prepared casserole pan.
Top chips with half of the chicken mixture and 1/3 of the shredded cheese.
Repeat the layering, ending with chips and cheese on top.
Bake Frito Casserole for 30 minutes.
When cooking is complete, serve with chopped fresh cilantro and toppings listed in the notes.
Notes
Add favorite toppings – While this busy weeknights dish needs no side dish recipe (it’s a pretty filling complete meal), serve it with guac, sour cream, hot sauce, chopped green onion, salsa, and black olives for toppings.