Combine ingredients for seasoning (A) and set aside. Heat 12 tablespoons oil in a wok and sauté combined seasoning (A) until fragrant. Add in water and bring to a boil for 23 minutes. Leave aside to cool completely.
Pour the cooked mixture into a baking tray. Fold the bean curd sheets into half and put into the mixture. Allow to soak for 56 minutes.
Carefully remove the soaked bean curd sheets and arrange them neatly on a lightly-greased table-top.
Roll up, then wrap with the muslin cloth and tie up with the string.
Place the wrapped roll on a plate and pour the remaining sauce over it. Steam over a gentle heat for 4050 minutes.
Remove, untie the string and unwrap. Leave to cool then cut into slices and serve.