1 medium-sized fish for steaming or frying (dart, snapper, bream, blackfish)
1 tablespoon flour
Oil for deep-frying
1 lime or lemon
1 cup (250 ml) water
1 tablespoon white vinegar
4 tablespoons sugar, or to taste
2 teaspoons light soy sauce
1 tablespoon cornstarch, more if you want a thinker sauce
Pinch each of salt and pepper
2 slices fresh ginger root, peeled and grated
2 cloves garlic, chopped
2 green onions cut diagonally into 1-in (2½ -cm) lengths
1 medium-sized tomato, cut into wedges
½ cucumber, unpeeled but halved, seeded and cut into fine strips
1 red chili, seeded and cut into fine strips
1 lemon, sliced
Fresh coriander leaves for garnishing
Clean, scale and dry the fish. Make 2-3 slashes through to the bone across each and dust with flour. Deep-fry the fish in hot oil in a wok until brown and crisp. Take out, drain and keep warm on a serving plate.
Cut 3 thin slices off the lime and squeeze the rest. Mix the juice with the water, vinegar, sugar, soy sauce, cornstarch, salt and pepper.
Drain all but 1 or 2 tablespoons of oil from the wok and fry the ginger and garlic until they are light brown. Add the green onions and toss them in the oil until coated. Add the tomato, the cucumber and the sauce and bring to a boil, stirring as it thickens. Pour the sauce over the fish immediately, garnish with chili strips, lemon slices and fresh coriander leaves and serve.