In a small mixing bowl, combine mustard, soy sauce and wasabi until the wasabi has dissolved. Cover and refrigerate.
Place cream cheese in a large bowl (preferably chilled metal). Mix in crab meat, onion, water chestnuts and parsley. Place one spoonful of the mixture in the center of each won ton wrapper. Bring points of the wrapper together (in a triangular shape) and pinch the edges closed. If the edges do not stick together, wet your fingertips lightly with water and pinch the ends together again (this will help to hold the won ton together).
Heat oil in a large skillet. When oil is hot, place won tons (approximately 6 at a time) into hot oil. Remove the won tons when they are golden brown. Drain them on a paper towel lined tray. Repeat this process until all won tons are fried. Serve with dipping sauce.
