Preheat the oven to 300°F. Have a braising pot or covered casserole dish on hand, or prepare a large baking dish by lining it with unbleached parchment paper.
In a skillet, heat the coconut oil over medium heat.
Season the chops on both sides with salt and pepper, then add them to the hot pan. Sear on both sides, working in batches if necessary to avoid overcrowding the pan. Place the seared chops in the braising pot, casserole dish, or prepared baking dish.
Combine the diced tomatoes and tomato paste in a bowl.
Cover the chops with the sliced onion and tomato mixture, then sprinkle on the thyme, oregano, and fennel.
Place the lid on the braising pot, casserole dish, or baking dish. If your baking dish does not have a tight-fitting lid, place another piece of parchment paper on top and tuck in the edges to create a seal. Braise in the oven for 2 hours, or until the meat is fork-tender. Serve over the parsnip mash, if you like, and garnish with the thyme sprigs.