Combine ginger, lemon juice, garlic, sugar and salt in a small saucepan. Bring to boil. Cover, reduce heat and simmer for 10 minutes to blend flavors. Blend cornstarch with a couple tablespoons of water. Stir into the ginger mixture. Stir over medium heat for 3 minutes or until thickened and there is no taste of the cornstarch. Pour over cooked fish.
To cook steaks brush with melted butter and bake in 425 F oven on a baking sheet for 10 minutes pet inch of thickness.