Bring 2 cups water to a boil in a medium saucepan. Add the sugar, salt, garlic and all the spices. Heat until sugar and salt are dissolved. Let cool. Add 3 cups of ice cubes. Pour brine into a sealable bag and add the pork chops. Refrigerate for at least 4 hours but overnight is best.
Take chops out of brine and dry them well. Let them come to room temp for 30 min before cooking.
In a large, heavy skillet (large enough to hold the chops with room to spare, preferably cast iron), heat the oil over high heat. Once it is shimmering and very hot, add the chops and turn the heat down to medium-high. Cook until beginning to brown, 5-6 minutes. Turn and cook until second side is beginning to brown, about 5-6 minutes. Keep turning chop every few minutes until both sides are deep golden brown and an instant-read thermometer inserted horizontally into center of meat registers 135°F (57°C). Transfer the chops to a plate and cover with foil to keep warm. The residual heat will bring the temp up to 145°F (63°C)
Carefully drain fat from skillet and place back over medium heat. Add butter and when melted, add onions and cook for 5-7 minutes until soft and translucent. Add the apples and garlic, cook until the onion is golden and the apple is softened, 5 minutes more. Then deglaze the pan with the beer or other liquid. Let the sauce cook and reduce for a dew minutes then stir in the mustard and the cream, if using.
Serve the chops with a large spoonful of the apple-onion sauce over the top.