Preheat the oven to 350 F. Spray the bottom and sides of a casserole dish with cooking spray.

Saute the onion and bell pepper in a tablespoon of butter

In a medium-sized bowl, mix the sauteed veggies, cooked chicken, cream of chicken soup, frozen veggies, mayo, and milk until well combined

Scoop the mixture into the prepared baking dish. Bake for 15 mins.

Remove the casserole from the oven and sprinkle half of the cheddar cheese on top of the chicken mixture.

Place the biscuits on top of the cheese

Top with the remaining shredded cheddar and bake for an additional 20 minutes or until the cheese is melted and the biscuits are brown and cooked