4 (3/4- to 1-inch-thick) center cut, bone-in pork chops (about 1/2 pound each)
3 cups cold water, divided
3 tablespoons kosher salt, plus more for seasoning
2 tablespoons maple syrup, divided
2 tablespoons minced peeled fresh ginger, divided
Freshly ground black pepper
2 tablespoons apple cider vinegar
2 tablespoons olive oil
1 garlic clove, minced
2 large sweet potatoes (about 2 pounds total), cut into 1-inch chunks
1 medium red onion, chopped
Bring 1 cup of the water to a boil in a small saucepan. Add the 3 tablespoons of salt, 1 tablespoon of the maple syrup, and 1 tablespoon of the ginger, and stir to dissolve the salt and syrup. Remove from the heat and add the remaining 2 cups cold water to bring the temperature of the brine down to room temperature.
Place the pork chops in a single layer in a shallow dish. Pour the brine over the pork chops, making sure they are completely covered. Cover and refrigerate for 30 minutes or up to 4 hours.
Arrange a rack in the middle of the oven and heat to 400°F. Remove the chops from the brine and pat them dry with paper towels. Season all over with salt and pepper.
Whisk the remaining 1 tablespoon maple syrup and apple cider vinegar together in a small bowl; set aside.
Heat the oil in a large cast iron or oven-safe skillet (large enough to fit all 4 chops) over medium-high heat until shimmering. Add the pork chops and sear until the bottoms of the chops are golden-brown, about 3 minutes. Flip the chops and cook until the second side is golden-brown, about 3 minutes more. Transfer to a plate.
Add the remaining 1 tablespoon ginger and garlic to the skillet and sauté until fragrant, about 30 seconds. Add the sweet potatoes and onion, season with salt and pepper, and sauté until the vegetables are tender, 6 to 8 minutes.
Return the pork chops to the skillet, nestling them among the vegetables. Pour the maple syrup and vinegar mixture evenly over the pork and vegetables. Carefully transfer the hot skillet to the oven and roast until the pork chops are cooked through and register 140°F to 145°F on an instant-read thermometer inserted into the thickest part of the meat, 6 to 10 minutes.
Remove the skillet from the oven, tent it loosely with foil, and let the chops rest 5 minutes before serving.