Melt the butter in a large skillet over medium-high heat. Add the onions and saute until translucent, about 7 minutes. Remove the pan from the heat and stir in the breadcrumbs, salt, pepper and garlic powder. Stir in the beaten egg and parsley.
To cut pockets into the pork chops, insert the point of a small sharp knife horizontally into the fat-covered edge. Move the knife back and forth to create a deep pocket about 1 1/2 inches wide.
Fill the pocket of each chop with the breadcrumb mixture. Secure the openings with toothpicks.
Place the flour in a shallow bowl. Dredge the stuffed chops lightly in the flour, shaking off the excess. Wipe out the skillet used previously for the stuffing and place it over medium-high heat. Add the oil and, when hot, add the chops. Sear over medium heat until lightly browned, about 3 minutes per side.
Place a rack in a roasting or baking pan and add water, being careful not to cover the rack with water. Place the chops on the rack and cover the roaster with the lid or aluminum foil. Bake the chops for 1 hour. Let rest, remove the toothpicks and serve.
If you don't have a rack, you can make rings out of foil and rest your pork chops on them to prevent the chops from sticking to the bottom of the pan.
Adapted from Georgia Cooking in an Oklahoma Kitchen by Trisha Yearwood (c) Clarkson Potter 2008