Preheat oven to 350°.
Melt the butter in a large stovetop skillet. Add the garlic, onion, celery and carrots. Cook over medium heat until tender (about 10 minutes).
Sprinkle the flour, salt, pepper, thyme and poultry seasoning on top of the cooked vegetables.
Add the chicken broth and cream. Whisk until there are no visible lumps of flour. Reduce heat to medium-low and simmer for 10 minutes.
Remove pan from heat and mix in the shredded rotisserie chicken and peas. If you are using an oven-proof pan or skillet, the next step can be completed in the pan/skillet. Otherwise, transfer the chicken pot pie gravy to a lightly greased casserole dish.
Remove the 8 biscuits from their canister and place on top of the gravy. Bake dish in pre-heated oven for 25 minutes or until bubbly and the biscuits are cooked through. You may have to broil at the end to brown the tops of the biscuits (depending on your oven).