Pat fish dry with paper towel and place on chopping board. With a sharp knife, make four diagonal slits into one side of the fish, then turn the fish over and repeat on the other side.
Place fish in a shallow heatproof bowl that will fit inside a steamer basket. Pour wine or sherry over fish, then sprinkle with half the ginger. Place bowl inside steamer and position over a deep saucepan or wok of boiling water and steam, covered, for approximately 7 minutes.
Cut each Chinese cabbage leaf into 4 squares and slip inside steamer. Cover and steam for a further 2-3 minutes, or until cabbage has warmed
through and fish is just cooked. The flesh should be white; if it is still translucent, cook for another minute or so.
Remove cabbage from steamer and arrange on a serving plate. Using a spatula, carefully remove fish from steamer and place on top of hot cabbage. Pour any liquid left in the bowl over fish, sprinkle with sugar and drizzle with combined shoyu and sesame oil, then sprinkle with remaining ginger and half the spring onion. Heat peanut oil in a small frying pan until moderately hot, then carefully pour over fish. Sprinkle fish with remaining spring onion, coriander and pepper, and serve immediately.