Preparation Mix first 6 ingredients in 8x8x2-inch glass baking dish. Add fish; turn to coat. Chill 2 hours, turning fish occasionally. Place steamer rack in large skillet. Arrange fish on rack. Pour marinade into skillet under rack and bring to boil. Cover skillet and steam fish until just opaque in center, about 8 minutes. Transfer fish to plates. Remove steamer rack from skillet. Boil marinade until reduced enough to coat spoon, about 6 minutes; spoon over fish. Top with green onions.