Melt butter in a large skillet over medium-high heat. Add onion and next 3 ingredients, Sauté 10 minutes or until vegetables are tender and liquid evaporates.
Remove from heat. Add stuffing mix and broth; stir until liquid is absorbed. Stir in sage, 2 tablespoons chopped parsley, 1/2 teaspoon salt, 1/2 teaspoon black pepper, and ground red pepper. Let stand 20 minutes.
Preheat oven to 375°F Trim excess fat from each pork chop, and cut a slit in 1 side of each chop to form a pocket. Spoon stuffing mixture evenly into each pocket.
Combine remaining 4 tablespoons parsley, 1/2 teaspoon salt, and 1/2 teaspoon black pepper. Rub both sides of stuffed pork chops evenly with 2 tablespoons oil, and spread parsley mixture evenly over chops.
Cook chops in remaining 2 tablespoons hot oil in a large nonstick skillet over medium-high heat, in batches, 2 minutes on each side or until browned.
Place on a lightly greased rack in a broiler pan. Add 1 cup water to bottom of broiler pan. Bake for 30 to 40 minutes. Let stand 5 minutes before serving.