In a skillet, cook bacon until crisp; remove with a slotted spoon to paper towel. Drain, reserving 2 Tbsp of drippings.
Sauté celery & onion in drippings until tender. Add mushrooms, herbs & seasoning; cook & stir for 5 minutes. Remove from heat; stir in stuffing mix, celery leaves, parsley & bacon. Add broth & gently combine. Set aside.
Preheat oven to 350 F. Grease a 13″ x 9″ baking pan or line with greased foil paper.
Wash & trim any excess fat from chicken leg quarters. Loosen skin over thighs to form pockets for the stuffing.
Fill thigh ‘pockets’ with stuffing & place in baking pan. Place any remaining stuffing around the 2 leg quarters to bake at the same time. Cover with foil for about 30 minutes then uncover & finish roasting until chicken is cooked through & stuffing is lightly browned.