Add brine ingredients to a stockpot and bring to a boil. Stir to dissolve sugar and salt, and remove from heat to cool completely. To quickly cool, add ice to hot brine.
Brine chops overnight in the fridge then remove from brine and pat dry. Coat chops in flour. Heat oil in a Dutch oven and brown chops in batches over medium-high heat, 3-4 minutes per side. Remove to a plate.
Preheat oven to 325ºF.
Melt butter into pork chop drippings and add onions, bay, salt and pepper. Cook to tender, 12-15 minutes, sprinkle in 4 tablespoons flour and stir a minute more. Deglaze pan with brandy or sherry if using, then slowly stir in 1/2 cup cider then chicken stock. Stir to combine. Slide chops back into sauce and cover, roast 1 1/2 to 2 hours until very tender.