Heat oven to 350. Lightly spray a baking pan w/ cooking spray. With a sharp knife, cut a pocket in each pork chop.
Melt butter in lg skillet over medium heat. Saute onions until soft. Add spinach to skillet and cook, stirring until wilted. Stir in stuffing mix, sour cream and sage.
Cook, stirring for 2 mins. Fill each pork pocket w/ 1/3 cup stuffing mix. Secure w/ toothpicks. Place chops on baking pan. Sprinkle w/ lemon-pepper seasoning. Bake 35-40 mins, or until chops are cooked through.