1 If using dried mushrooms, soak for 20 minutes in hot water until soft, then drain. Blanch carrot and set aside. Soak mussels or clams for 5 minutes in 4 cups cold water mixed with 2 tablespoons salt. Rinse under cold running water and drain. Blanch shirataki noodles for 2 minutes, remove from water, and when cool enough to handle, cut into 10-cm (4-in) lengths.