Scrub and place the clams in salted water (1 tablespoon of salt in 2 to 3 cups of water) for 30 minutes or longer to get the clams to spit out the sand. Separate the top shell from the crab and remove the gills. Clean the shell part thoroughly, with a kitchen brush or a toothbrush, under running water. Break (or cut) the body in half (or quarters). Clean the squid and fish, and cut into bite size pieces. Clean the shrimp.
Cut the cabbage, radish, carrot into thin, bite size pieces. Thinly slice the onion and mushrooms. Cut the scallion in similar lengths.
Mix the seasoning ingredients well with 2 to 3 tablespoons of the broth or water.
Using a wide, shallow pot, neatly arrange the vegetables in clusters, with the exception of the watercress (or crown daisy).
Scatter the seafood pieces on top of vegetables, placing the clams/mussels closer to the bottom of the pan. Add 3 cups of broth and the seasoning paste, reserving 1 tablespoon to add as necessary to your liking. Top it with the watercress (or crown daisy), and cook over medium high heat until the clams/mussels are open, the fish is cooked through and the vegetables are softened. Drizzle the optional lemon juice over. Stir occasionally.
You can add more broth and any remaining ingredients while eating if you’re cooking at the table.
This seasoning paste will be great for any Korean spicy stew or soup. Double the recipe and save one half for later use. Keep it in an air tight container.