• Preheat the oven to 350℉.

Make the Filling

• Add the butter to a large skillet over medium-high heat.
  1 tablespoon butter
• Once melted, add the sliced onions and sauté for 3-5 minutes or until they're softened a bit.
  1/2 cup sliced onions
• Add the mushrooms and garlic; continue to cook, stirring occasionally for 5 minutes.
  8 ounces sliced mushrooms, 1 tablespoon minced garlic
• Remove the skillet from the heat and add the spinach, bread crumbs and parmesan cheese; set aside.
  1 cup chopped spinach, 1/2 cup panko bread crumbs, 1/4 cup grated parmesan cheese

Stuff the Pork Chops

• Place the pork chops on a cutting board.
  4 thick cut pork chops
• Hold the pork chop steady with one hand and use a sharp knife with the other hand to cut horizontally to form a pocket. Be careful not to cut all of the way through when using a boneless pork chop. If you're using a bone-in pork chop, cut all the way to the bone to form a large pocket. Repeat until all of the pork chops are done.
• Divide the filling between the four pork chops (about 1/3 - 1/2 cup per chop).
• Add a slice of cheese into the pocket as well and press the pork chop down to close it nice and tight.
  4 slices mozzarella cheese
• Season the pork chops with salt and pepper on both sides.
  salt and pepper

Cook the Pork Chops

• Place a clean skillet on medium-high heat.
• Add a drizzle of vegetable oil into the pan (if using a nonstick skillet, you may not need any).
• Add the pork chops and cook for 2-3 minutes on each side.
• If you're using an oven-safe skillet, you can cover it with its lid and place in the oven. If not, transfer the chops to a baking pan and cover tightly with aluminum foil.
• Bake until the pork chops reach 145℉. The baking time will vary greatly depending on the thickness of the chops and whether or not you kept them in the hot skillet. Check the pork chops after 10 minutes and go from there. (I like to use really thick chops and transfer them to a ceramic baking dish and they take about 25 minutes in the oven.)
• Let the pork chops rest for 5 minutes before serving.