Squeeze all excess liquid from the frozen spinach then chop it roughly. In a small skillet, heat the olive oil on LOW and cook the red onion slices until soft.
Combine the spinach with cream cheese and parmesan cheese, then season with salt and pepper. Fill each pork chop with the spinach-cream cheese mixture and seal it with toothpicks.
Heat the olive oil in a skillet on HIGH, then sear the pork chops for 2 minutes on each side. Transfer the stuffed pork chops to a baking tray and bake in the preheated oven for 10 minutes until cooked.