This is my take on a Korean classic. The broth is filled with intricate spices that stay fresh for months. Here I'll tell you how to shop for these worthwhile ingredients and prepare a traditional, spiced dish that will warm the entire family.
Cut the brisket into two or more pieces against the grain, so that the grain is about 2 inches in length. Season with salt and pepper and mix with the garlic, soy, and sugar. Turn to coat all sides.
Heat a large, heavy-bottomed pot over medium heat and add the oils. Add the onion and cook, stirring, until translucent, about 7 minutes.
Add the garlic and red pepper flakes and cook until aromatic, stirring frequently. Add the brisket, water, the anchovies, kombu, and scallion whites. Bring to a boil, then turn to a simmer until the brisket is fork tender, about 3½ hours, adding water as necessary to keep the meat submerged.
Remove the meat and shred into bite-sized pieces. Remove and discard the kombu. For the broth, add the fish sauce and soy sauce to the cooking liquid. Taste and add more sugar, salt and pepper as needed. Add the daikon and bring back to a boil. Add the zucchini and bring back to a boil.
In a medium saucepan, bring water to a boil; add enough salt to make the water as "salty as seawater." Add udon noodles to reheat according to package instructions. Divide the udon among 4 soup bowls; then top with the shredded meat, broth, and cooked vegetables. Garnish with scallion greens and serve immediately.