Preheat your barbecue to medium-high.
Set the scallops in a barbecue-safe pan or skillet. Place the wine, butter, garlic, cayenne and tarragon in a small pot and warm over medium heat, just until the butter melts. Pour this mixture over the scallops. Set the pan or skillet on the barbecue, close the lid and cook the scallops 5 to 6 minutes, or until just cooked through.
Sprinkle with parsley and serve.
Recipe Options: Make pan-barbecued Vancouver Island scallops and prawns by replacing six of the scallops with six, large peeled prawns. If don't wish to use wine, replace it with an equal amount of chicken stock or clam nectar. Instead of tarragon, try flavouring the scallops with dill.