Cut open each squid tube lengthways to form a flat sheet and score the inside of the squid in a criss-cross pattern, then cut into 2.5 cm/1 inch squares.
Cut the water chestnuts in half and thinly slice the bamboo shoots.
Heat a wok, add a little vegetable oil and stir-fry all the vegetables for a couple of minutes or so, then remove from the wok, dra