Rinse steaks, pat dry with paper towels and then sprinkle with salt.
Place the steaks on a heatproof plate that would fit in your steamer. Spread green onions and ginger over the fish.
Put the plate in the steamer and steam the fish for 15 minutes or until fish flakes easily with a fork. Gently transfer the cooked fish (minus the accumulated water) on a serving platter.
In a sauce pan, combine ingredients for the sauce. Let it boil and then pour over the fish. Serve with a garnish of julienned green onions and ginger.