Add the chicken breasts to the slow cooker.
Layer the potatoes, onion, celery, and garlic over the top.
In a bowl, stir together the cream of chicken soup, cream of mushroom soup, chicken broth, and seasoning. Pour the mixture into the slow cooker.
Cover and cook on LOW for 6–8 hours or HIGH for 3–4 hours, until the chicken is cooked through and tender.
During the last hour of cooking, remove the chicken and either shred or chop it into bite-sized pieces.
Return the chicken to the slow cooker, then stir in the frozen peas, carrots, and corn. Cover again and cook until veggies are done.
While the pot pie finishes cooking, prepare the biscuits according to the package directions.
Finish with a sprinkle of fresh herbs, if you like, and serve the chicken pot pie warm with the biscuits on the side.