Place 1/4 cup salt and brown sugar in a medium heatproof bowl. Pour in boiling water and stir to dissolve. Add ice cubes and stir to cool. Add pork chops, cover and refrigerate for at least 30 minutes or up to 4 hours.

Puree peaches, tomato and vinegar in a food processor until smooth.

About 30 minutes before you're ready to cook the pork chops, heat oil in a medium saucepan over medium-high heat. Add onion and cook, stirring occasionally, until golden brown, 5 to 7 minutes. Add ginger and cook, stirring frequently, until fragrant, 1 to 2 minutes. Add the peach puree, the remaining 1/2 teaspoon salt, honey and pepper to taste. Bring to a boil over high heat, then reduce the heat to a simmer. Cook until reduced by about half, 20 to 25 minutes. Reserve 1/4 cup of the sauce for basting the chops; keep the remaining sauce warm in the saucepan until ready to serve.

Preheat grill to medium.

Remove the pork chops from the brine (discard brine), rinse well, and thoroughly dry with paper towels. Season the chops with 1/4 teaspoon pepper and brush both sides with some of the reserved sauce.

Grill the pork chops, turning once, until an instant-read thermometer inserted into the center registers 145 degrees F, 2 to 4 minutes per side. Transfer to a plate, tent with foil and let rest for 5 minutes. Serve with the warm peach barbecue sauce on the side.

MAKE AHEAD TIP: Brine the pork chops (Step 1) for up to 4 hours. Refrigerate the peach barbecue sauce (Step 3) for up to 5 days.