Combine Seasoning Sauce ingredients. Let stand 1 hour, then discard ginger, garlic, scallion and most of cilantro.
Clean whole fish well under cold running water. Clean cavity and gill areas; remove any scales near head and tail. Score fish on both sides with diagonal score marks 1 inch apart and to within 1/4 inch of bone.
Fry ginger threads in 350°F oil about 10 seconds just until light golden; spread on paper towels to crisp and drain. Set aside.
Arrange the whole fish or fish fillets on heat-proof plates. Portion the Seasoning Sauce evenly over the fish, spooning the beans on top. Steam the fish in a steamer or perforated hotel pan over medium-high heat until a knife thrust in the thickest portion shows the fish to be done, about 12 to 15 minutes for whole fish. Transfer fish and its juices onto heated serving plates. Sprinkle fried ginger on top, then decorate with scallion threads and/or cilantro.