Boil the water (5 cups) and when it starts to boil add the mussels. When the mussels open their shells, sieve the water through a cloth strainer to get rid of the sand that comes out of the mussels. Keep this boiled water for later.
Add the boiled water (from step 1) into a clean pot, add the dried kelp, and boil it for 2-3 minutes. Take out the kelp and discard.
Add the radish and the hot pot sauce. Stir it well to dissolve.
Add the remaining vegetables, prawns, and cooked mussels into the pot and when it starts to boil, you can start eating the cooked ingredients. Enjoy!