Boneless salmon japonaise with creamed green onions

1/2 cup reduced-sodium soy sauce
1/4 cup sugar
1/4 cup lemon juice
1/4 cup white wine or sake
2 shallots, diced
2 cloves garlic, diced
1 tablespoon grated ginger
4 salmon fillets, about 8 ounces each
Vegetable oil for brushing salmon
For the creamed green onions:
1 tablespoon butter
12 green onions, trimmed and cut into 2-inch pieces
Salt and pepper
1/3 cup heavy cream
1 tablespoon water
1/2 teaspoon cornstarch
2 tablespoons chopped chives

1. In a mixing bowl combine soy sauce, sugar, lemon juice, wine, shallots, garlic, and ginger; mix well. Place salmon fillets in a resealable plastic bag. Pour marinade over salmon. Seal bag and marinate in refrigerator for 2 hours.
2. Just before grilling salmon, make the creamed green onions: In small saucepan melt butter. Add green onions and cook over low heat 3 to 5 minutes or until opaque. Season with salt and pepper. Add cream and stir to heat through. Keep warm.
3. Remove salmon from marinade; reserve marinade. Brush marinated fillets lightly with oil. Place fillets in center of cooking grate. Grill 6 to 10 minutes or until fish is opaque and flesh flakes easily with a fork, turning once halfway through grilling time.
4. Meanwhile, process marinade in blender or food processor until smooth. Pour into a small saucepan and bring to a boil; simmer one minute. In small bowl combine water and cornstarch. Add cornstarch mixture to heated marinade; stir until slightly thickened.
5. To serve, pour some marinade on each plate, top with some creamed green onions, top with salmon fillet, and sprinkle chives over each fillet.