For filling, in a mixing bowl combine soy sauce, cornstarch, curry powder, sesame oil (if desired), and sugar. Finely chop slaw. Add slaw, chicken, and onion; mix well. Cover; chill for up to 24 hours.

Spoon 2 teaspoons filling onto each wrapper. Moisten edges with water. Fold wrappers in half over filling. (For wontons, fold one corner over filling to opposite corner.) Fold pleats along edges; press to seal.

Arrange potstickers, pleated edges up, on a lightly floured baking sheet, pressing gently to flatten bottoms. Cover and chill until ready to cook. (Or, place on baking sheet; freeze for 30 minutes or until firm. Transfer to plastic freezer bag or airtight freezer container; seal, label, and freeze up to 1 month. Let thaw for 30 minutes before cooking.)

In a 12-inch skillet heat 2 tablespoons oil. Arrange half of the potstickers, pleated edges up, in skillet. Cook, uncovered, over medium heat for 1 to 2 minutes or until bottoms are light brown. Reduce heat to low.

Remove from heat; carefully add 2/3 cup water all at once near edge (oil may splatter). Return to heat. Cover; cook 10 minutes more. Increase heat to medium-high. Uncover; cook 3 to 5 minutes or until filling is no longer pink and water is evaporated.

Add 2 teaspoons oil. Lift and tilt skillet to coat potsticker bottoms. Cook, uncovered, 1 minute more. Gently remove potstickers from skillet. Drain on paper towels. Keep warm in a 300 degree F oven. Makes 30 appetizers.