To Prepare the filling: Mix together all ingredients except wonton skins and vegetable oil until meat and water chestnuts are combined into a uniform mixture. Divide into 30 portions.
Put 1 tablespoon of the filling in the middle of a wonton skin. Diagonally fold the skin in half to form a triangle. Fold the edge containing the filling over about 1cm. Bring the 2 points together moisten one inner edge and pinch the edges together to hold. Repeat with remaining wontons and filling.
Heat a wok, then add the vegetable oil. Deep fry the wontons over a medium heat until golden. Drain on paper towels and serve.