Wash salmon under cold water, then dry completely, cover, and place back in the refrigerator.
In a small bowl, combine all marinade ingredients and mix together thoroughly.
Roll out two sheets of foil that are about 4-6 inches longer than the fillet. Fold the edges of the foil up so it makes a shallow tray.
Drizzle olive oil on the bottom, then place fillet on top. Salt and pepper the top of the fillet, then pour marinade over the salmon.
Preheat the barbecue to high—450 to 475 degrees. When the barbecue is fully heated to high, place salmon inside and close the top. Barbecue for about 10 minutes, then remove, garnish with green onion, and serve immediately.