Combine 2 sheets of kombu seaweed in 2000 ml of water. Soak for 2 hours, then turn on the heat to boil. Reduce the heat to the lowest once the kombu starts swimming in the pot. Heat for 5 minutes.
If you put 1 cup of bonito flakes into a clean empty tea bag, it's easy to make dashi stock. Burn off the alcohol from the sake and mirin to enhance the flavor.
Prepare the crab. Place the bottom of the knife blade on the joints and you should be able to cut the crab legs easily. Kitchen scissors also work well.
Make slits on the shells of crab legs with a knife. Move the blade so as to peel off the shell (if you think it is difficult, cut the leg joints lengthwise).
Add the bonito flake sachet into the dashi stock and simmer for 5 minutes over low heat. Add all the seasonings for the soup stock and bring to a boil. Transfer the soup stock to a bowl and leave to cool.
If you add the crab shells and trimmings to the dashi, it'll enhance the flavor. Meanwhile, prepare the vegetables.
Put all the ingredients except the crab and mizuna leaves in a clay pot. Pour in the soup stock. Add the crab after the ingredients are cooked through about 80%.
Bring back to a boil, add the mizuna and cook in residual heat. Do not overcook the crab. Serve with plenty of soup!
Prepare your rice porridge with the remaining soup at the end. Rinse cooked rice to remove any stickiness or gluten. Add the rice to the pot and bring back to a boil. Turn off the heat and add a beaten egg and mitsuba. Cover with a lid to steam through.
Make stewed tsukudani kombu with the used kombu (Recipe ID: 1337375).
Make a furikake seasoning for rice with your used bonito flakes (Recipe ID: 1025143).
Story Behind this Recipe
To be honest, I prefer the zosui rice more than the hot pot itself. Crab hot pots are especially delicious to make zosui with.
-Do not overcook the crab, otherwise it'll dry out! -When you prepare crab, use kitchen scissors. It will be easier.