Fill a pot with the water. Add the seaweed kelp and bonito flakes and bring to a boil. Remove the seaweed kelp and bonito flakes from the stock and add the sake, mirin and soy sauce. Stir well and set aside.
Brush the abalone clean and rinse quickly under running water. Steam the abalone with the seaweed kelp and Japanese turnips for 3 hours.
Put these ingredients into the soup and bring to a boil, then reduce the heat and simmer for around 2. hours, or until the abalone is soft.
Slice the abalone and set aside.
Combine the sake and clams in a pot and boil for 15 minutes over high heat. Remove the clams and strain the soup through a fine sieve. Cook the clam soup with the agar agar until melted, then pour the liquid jelly base into a shallow container. Cool in the fridge for at least 2 hours.
Place a scoop of steamed rice into a hot stone bowl. Plate the sliced abalone on top of the rice. Remove clam jelly from the container and, using a small circular cutter, cut slices around the size of your rice and abalone and place it on top. Re-heat the soup and pour it over the bowl just before serving.