Prepare marinade by mixing olive oil, minced garlic, chopped rosemary, thyme leaves, salt, and pepper in a bowl.
Coat Costco lamb chops with the marinade, then refrigerate for a minimum of one hour.
Preheat the grill to medium-high heat.
Remove excess marinade from the lamb chops before placing them on the grill.
Grill the lamb chops for about 3-4 minutes on each side for a medium-rare result.
Serve the Costco lamb chops.