Preheat barbecue to high heat. Rinse the salmon under cold water and pat dry. Trim off the tail and fins. Make several shallow cuts through the skin. Place on 3 large, slightly overlapping sheets of aluminum foil. Combine the remaining ingredients, except green onions, in a small bowl; spoon over the salmon. Fold the foil over the salmon and crimp the edges to seal. Place the package on one side of the barbecue and turn the heat off directly underneath it. Close the lid and cook 25 to 30 minutes, or until cooked. Open the foil and carefully transfer the salmon to a platter. Carefully pour any juices in the foil over top. Sprinkle with green onions and serve.