Heat peanut oil in a wok. Sizzle the ginger & garlic briefly then add tofu & stir-fry for a few minutes. Add scallions, sesame oil & tamari & stir well. Set aside to cool.
Set up a work area with wonton wrappers, water & cornstarch. Place a wrapper in front of you in a diamond position. Drop a heaping teaspoonful of filling in the centre of the wrapper. Moisten all 4 edges with water & pull the top corner down to the bottom, folding the wrapper over the filling to make a triangle. Press edges firmly to make a seal. Bring left & right corners together above the filling. Overlap the tips of these corners, moisten with water & press together. Place completed wrapper on the corn-starch platter & continue till all wrappers are used.
FOR SOUP: Drop wontons into boiling water & cook for 5 minutes. Drain.
TO FRY: Heat 2 to 3 cups of oil in a wok till hot. Deep fry wontons in batches till golden, 2 to 3 minutes on each side. Drain. Serve with dipping sauce or duck sauce.
Uncooked wontons will keep in the freezer for a good 2 months if well wrapped. Thaw before frying, but they can be boiled straight from frozen & cooked 2 minutes longer.