Saute Chinese mushrooms in oil until fragrant. Set aside.
Boil the water in a nonstick pot. Add the mushrooms, ginger juice, wine, maltose and black soya sauce. Stirring constantly in one direction, cook over low fire till the mixture thickens. Do not overcook or the seaweed will be bitter.
Dish up onto a heatproof dish and steam the mixture for 30 minutes.
Variation: Seaweed sheets used in Chinese cooking (round black discs) can also be used as a substitute but the paste would be coarser due to the texture of the seaweed. The Chinese seaweed sheet is said to be inferior to nori sheets. Also, you have to steam the Chinese seaweed for two hours to soften it.
Tip: Stir the seaweed mixture in one direction for a smooth paste. If you stir haphazardly, the paste will have a coarser texture.