1.Place Tuna Steaks In A Steamer Over 1 Inch Of Boiling Water, And Cover. Cook 6 To 8 Minutes, Or Until Fish Flakes Easily With A Fork. 2.Meanwhile, In A Medium Saucepan, Combine Soy Sauce, Sherry, Vegetable Oil, Green Onions, Ginger, Garlic, Salt, And Black Pepper. Bring To A Boil. 3.Remove Tuna Steaks From Steamer, And Place In A Serving Dish. Pour Sauce Over Tuna Steaks, And Serve Immediately.