Mix together the coriander seeds, soy sauce, garlic and sugar. Put the chops on a plate and spoon the coriander mixture over them. Leave for 30 minutes, turning once. Reserve the marinade.
BBQ the chops for 2 minutes on each side on a hot heat. Move to a cooler part of the BBQ for a further 8 minutes on each side or until the pork is cooked through and tender; baste occasionally with the marinade.