Place the chicken pieces, carrots, celery, onion, chicken broth, thyme, salt, and pepper into the slow cooker. Stir once to combine.
Cover and cook on low for 6 to 7 hours until the chicken is cooked through and the vegetables are tender.
Stir in the frozen peas and heavy cream. Let the stew cook for 10 more minutes with the lid on.
While the peas warm, bake the biscuits according to the package directions on a baking sheet until golden.
Ladle the stew into bowls and place one or two warm biscuits on top of each serving.