Heat the oil in a large non-stick skillet or wok set over medium-high. Add the scallops and cook 1 minute per side, and then remove and set aside. Add the ginger, garlic and chili sauce to the skillet or wok and cook for 30 seconds. Add the black bean sauce and water and bring to a simmer. Return the scallops to the skillet or wok and cook 1 to 2 minutes more, or until cooked through. Toss in the green onions and serve.