1. Combine celery, scallions, garlic, soy sauce, oil, sherry, ginger and sugar in a bowl and set aside.
2. Gently make three or four small diagonal slices along both the sides of the fish, with a sharp knife.
3. Place the fish in a shallow baking dish.
4. Spoon the vegetable mixture, prepared before, over the fish.
5. Place 4 inverted custard cups in a large wok.
6. Set the baking dish on top of the cups.
7. Add very hot water to the wok, about 1 inch deep.
8. Cover the wok and bring the water to a boil, over high heat.
9. Reduce the heat and steam the fish for 25 minutes.
10. Chinese Style Steamed Fish is ready.