Adapted by author Paul Greenberg from a recipe by About.com Korean food expert Naomi Imatome-Yun.
Ingredient-wise, the daikon radish, zucchini and chili peppers are a must. But you can add whatever other vegetables you like, including soybean sprouts, pumpkin, mushrooms and watercress, as well as other shellfish, such as oysters and clams.
1 large fish head (about 1 1/2 pounds)
1 fish rack (optional; see headnote)
8 cups water
1/2 block (7 ounces) firm tofu
8 ounces daikon radish, peeled and cut into 1-inch pieces that are 1/8-inch thick
1/2 zucchini, halved lengthwise, then cut into 1/4-inch slices
1 small red chili pepper, seeded if desired, then cut thinly on the bias
1 small green chili pepper, seeded if desired, then cut thinly on the bias
1 sweet onion, cut into strips
2 scallions, cut into 1-inch pieces
2 cloves garlic, crushed and chopped
1 tablespoon regular or low-sodium soy sauce
1 tablespoon gochugaru (Korean crushed red chili pepper powder)
3 tablespoons gochujang (Korean chili pepper paste)
4 ounces edible chrysanthemum leaves (optional)
Kosher or sea salt
Freshly ground black pepper
3 tablespoons chopped fresh cilantro, for garnish
Rinse the fish head and pat it dry.
Use your fingers and/or a small paring knife to extract any flesh from fish head and the collar. If you are also using a fish rack, you can extract a significant amount of flesh from it by holding one end and strumming your fingers along the bones. Reserve all of the flesh in a bowl.
Place the picked-over fish head and rack in a stockpot, then add the water. Bring to a boil over medium-high heat; cook for 10 minutes, turning the head over once during that time. (If you like, you can use a spoon to remove the fish cheeks about halfway through cooking. Add them to the flesh reserved from the head and collar.)
Meanwhile, wrap the tofu in paper towels and use a heavy plate to weight it (to help extract any liquid).
Strain the cooking liquid through a fine-mesh strainer into a separate pot; discard the bones. Bring to a boil over medium-high heat, then add the radish, zucchini, chili peppers, sweet onion, scallions, garlic, soy sauce, gochukaru and gojuchang; reduce the heat to medium and cook for 6 or 7 minutes, until the vegetables are tender.
Reduce the heat to medium-low. Stir in the reserved fish flesh; cook for about 2 minutes or until it is tender and opaque.
Unweight/unwrap the tofu and cut it into large cubes. Add them and the edible chrysanthemum, if using, to the pot; cook for 2 to 3 minutes without stirring.
Season lightly with salt and pepper. Divide among individual bowls. Garnish each portion with the cilantro. Serve hot.