1. Trim off the ends of the celery stalks and their leaves. Scrub well under running cold water. Use a potato peeler to remove the outer layer, making sure there are no strings left.
2. Cut lengthwise in 4 equal strips, then cut these into large matchstick pieces about 1 3/4 in (5 cm) long.
3. Heat the oil in a non-stick frying pan and stir-fry the celery for 1 1/2 minutes. Sprinkle with the soy sauce and sake, turn up the heat a little more and reduce what little liquid there is so that the celery is just moist.
4. Add a pinch of sugar and a pinch of the taste powder, if wished.
5. Stir once more and serve on 4 individual plates. This is very good cold or hot, served with plain boiled or steamed rice.