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, separate them, and place on top of chicken stew. Line them evenly over top.
Place the pie on a foil-lined baking sheet and bake for 14-16 minutes until the biscuits are real 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 into each bowl and top with 1 biscuit. There will be two extra biscuits for whoever wants it.