Place the chicken breasts into the bottom of your slow cooker. Add the diced potatoes, celery, chopped onion, and frozen vegetables right on top.
In a small bowl, whisk together the cream of chicken soup, milk, garlic powder, poultry seasoning, salt, and pepper. Pour this mixture evenly over the vegetables and chicken.
Cover the crockpot with the lid. Cook on low for 6 to 8 hours or on high for 3 to 4 hours. No stirring needed during cooking.
Once the chicken is fully cooked and tender, use tongs to remove it. Shred it using two forks and return it to the slow cooker. Stir everything together to combine the shredded chicken with the creamy filling.
While the filling finishes cooking, bake your biscuits in the oven according to the package instructions.
Spoon the hot filling into bowls. Place a warm biscuit on top of each serving. Serve immediately for the best texture and flavor.
