Prepare a grill fire to 350° using hickory or oak for smoke flavor.
Pat pork chops dry with paper towels and place on a rimmed sheet pan.
Brush olive oil over pork chops on both sides. Season the pork chops with dry rub, reserving 1 tablespoon of rub for the peaches.
Make the Cowboy Butter: Melt butter with minced garlic, cook over low heat for 4-5 minutes.
Remove from heat and whisk in horseradish, dijon mustard and dried thyme. Add parsley and red pepper flakes.
Grill the Peaches: Wash peaches and cut in half, score the peach halves in a grid pattern. Place in a foil pan or foil packet. Top with melted butter and sprinkle with remaining tablespoon of dry rub. Cook on a hot grill until peaches are softened.
Grill the Pork Chops: Grill pork chops over indirect fire with the grill closed for 5 minutes.
Flip the pork chops and top with cowboy butter. Continue to cook with the grill closed until pork chops reach 145° using a digital meat thermometer.
Remove pork chops from the grill. Top with additional cowboy butter if desired.
Slice peaches into bite-sized pieces and serve over pork chops.