If you look at the cut side of the daikon from above, you can see a loop of fibre inside the peel. Use a knife to remove that part, along with the skin. Make a crisscross incision on one side of the daikon, which will help the daikon to cook faster.
Place the piece of kombu in the base of a saucepan and add the daikon, with the incision side down. Pour over enough water to just cover th