Coat a large pot or Dutch oven with peanut oil over medium-high heat. Add the garlic, celery and onions. Cook until the vegetables are browned, about 5 minutes. Add the shanks to the pot along with the salt, peppercorns, bay and thyme. Pour in the chicken broth and wine, then add enough water to just barely cover the shanks. Bring to a boil then reduce heat, cover and simmer for 1 hour 30 minutes.
Remove the shanks from the pot and set on a wire rack over a sheet tray. Allow the shanks to drain and cool, 25 to 30 minutes. If you have time, you can also place the shanks in the refrigerator, uncovered, for 2 to 3 hours (this will really help dry the outsides of the shanks so that when you fry them they will get super crispy and also won't splatter as much).
Pat the cooled and drained shanks dry with paper towels. Sprinkle with salt and pepper. Heat 3 inches of peanut oil in a deep, heavy pot, such as a Dutch oven or tall stock pot, to 350 degrees F. Working in batches, carefully add the shanks to the pot, skin-side down. Cover and leave slightly ajar until the oil settles. Cook, turning once, until the shanks are golden brown and crispy, 10 to 15 minutes. Drain and season with salt. Repeat with the remaining shanks. Serve crispy fried pork shanks with the Fried Caper and Lemon Gremolata and chimichurri sauce if using.
Fried Caper and Lemon Gremolata:
Place the golden raisins in a bowl of hot water with 1 tablespoon of the honey and gently squeeze them with the back of a spoon to plump them back up. Rehydrate for 2 to 3 minutes. Drain and set aside.
Heat 1/2-inch oil to 350 degrees F in a saute pan over medium-high heat. Fry the capers for 30 to 45 seconds. Drain and set aside.
Combine the parsley, lemon zest, lemon juice, shallots, garlic, remaining 1 tablespoon honey, fried capers and raisins in a mixing bowl and stir. Season with salt and pepper. Drizzle with the olive oil and set aside to allow the flavors to come together, 10 to 15 minutes.
If using a pressure cooker, follow the same directions but cut the braising time in half. Do not overcrowd the pot when frying the pork. It's best and safest to work in as many batches as you need to prevent a grease fire in the kitchen.