Preheat oven to 350º. Spray cookie sheet with cooking spray, set aside.
Spray a skillet with cooking spray and cooked diced onion until soft. Add remaining ingredients and heat through.
Open package of biscuits and flatten each circle out with your fingertips. Place chicken filling on one half of the circle and bring the other half over. Press edges with a fork to seal closed. Carefully place on the cookie sheet.
Finish each mini pot pie and then bake for about 30-35 minutes or until the outside is golden and the middle is cooked. Serve immediately and enjoy!