How to Make It
In a medium bowl, whisk the apple cider with the light brown sugar and 1/4 cup of kosher salt until the salt and sugar are dissolved. Pour the brine into a large plastic bag. Add the pork chops, seal and refrigerate overnight.
Light a grill. In a small saucepan, combine the yellow and whole-grain mustards with the dark brown sugar, cider vinegar, water, Worcestershire sauce and garlic. Simmer over moderate heat, stirring occasionally, until thickened, about 10 minutes. Stir in the butter and season with Tabasco and salt and pepper. Keep warm.
Remove the pork chops from the brine and pat dry with paper towels. Season the chops with salt and pepper. Grill over high heat until the pork is nicely browned, about 5 minutes per side. Reduce the heat to moderate or, if using a charcoal grill, move the coals to one side and transfer the pork chops so they're opposite the coals. Continue cooking the chops until an instant-read thermometer inserted in the thickest part of the chops registers 145° for medium-well, 10 to 15 minutes. Let the chops rest for 5 minutes, then serve with the warm mustard sauce.