Preheat oven to 350 degrees. In a large pan, add chicken broth and bring to a boil.
Stir in onions, potato, sweet potato, carrots, and celery. Bring back to a boil, reduce heat, and cover. Simmer for 6 minutes.
Add chicken pieces and frozen peas, breaking them up. Bring back to a boil, turn heat to simmer, cover, and cook for 5 minutes.
Place a colander into a large bowl. Pour chicken, vegetables, and broth into a colander. Add strained broth back to the pan. Set aside chicken and vegetables.
In a separate small bowl, add flour. Gradually add milk to the flour stirring with a whisk, until well blended.
Increase heat to medium with the broth. Stir in milk/flour mixture with a whisk. Cook for 5 minutes or until thickened. Stir often.
Add back chicken and vegetables, along with thyme, salt, and pepper. Mix well.
Coat an 11 x 7 baking dish (see Shopping Tip) with cooking spray and pour in the chicken stew.
Open the package of biscuits. Place 8 biscuits evenly over the chicken stew. Set aside the 2 remaining biscuits to bake separately, if desired.
Place the pie on a foil-lined baking sheet and bake for 14-16 minutes until the biscuits are golden brown. Note: If they are not browned enough for your liking, or they still don’t bake completely, remove and place biscuits on a baking sheet and continue to bake in a 350-degree oven until real golden brown, about 6-10 minutes. Or bake biscuits separately on a baking sheet while the casserole is baking. If baked separately, follow biscuit instructions.
To serve, spoon the chicken pot pie into 8 bowls and top each serving with 1 biscuit.