Bring water to a boil in a medium saucepan. Add kosher salt, sugar, rosemary, peppercorns, halved head of garlic, and thyme; stir to dissolve salt and sugar. Transfer to a medium bowl and addice cubes. Stir until brine is cool. Add pork chops; cover and chill for at least 5 to 6 hours.
Preheat oven to 425°F (220°C). Set a wire rack inside a rimmed baking sheet. Remove chops from brine; pat dry. Heat oil over medium-high heat in a large cast-iron or other oven-proof skillet. Cook chop until beginning to brown, about 2 minutes. Turn and cook until second side is beginning to brown, about 2 minutes. Keep turning chop every 2 minutes until both sides are deep golden brown, 10-12 minutes total.
Transfer skillet to oven and roast chops, turning every 2 minutes to prevent it from browning too quickly, until thermometer inserted horizontally into center of meat registers 135°F (57°C), about 14 minutes.
Carefully drain fat from skillet and place over medium heat. Add butter, 2 unpeeled garlic cloves, ghost chili, cranberries, tea leaves and chili flakes; cook until butter is foamy. Carefully tip skillet and, using a large spoon, baste chops repeatedly with butter until butter is brown and smells nutty, 2-3 minutes.
Transfer pork chop to prepared rack and let rest, turning often to ensure juices are evenly distributed, for 10 minutes. Serve as-is after resting or sliced with some roasted potatoes and wilted greens.