1-First Step: Soak the beef brisket in water for 10 minutes to remove blood, then drain. In a medium pot, combine 4 cups water, brisket, 20 g onion, 5 g green onion (white part), and 10 whole black peppercorns. Bring to a boil and skim off any scum for a cleaner broth.

2-Second Step: Reduce to medium-low heat and simmer for about 1 hour until the brisket is tender. Strain the broth and let it cool for 30 minutes.

3-Third Step: Remove the meat, trim off excess fat, and thinly slice it. The slices will become a topping when you assemble the Korean naengmyeon cold noodle soup bowls.

4-Fourth Step: Mix the cooled beef broth with 2 cups dongchimi (radish water kimchi brine). Add 2 tablespoons vinegar or apple cider vinegar, 1 tablespoon pear juice, 1 1/2 tablespoons sugar, 1/2 teaspoon fine sea salt, and 1/4 teaspoon mustard powder. Taste and adjust seasoning based on what you love, especially if your dongchimi is more tangy or more mellow.

5-Fifth Step: Cover and freeze lightly for 3 to 4 hours until icy cold and slightly slushy. If you want to serve fast, you can also chill in the fridge for longer, but the freezer helps the broth get that characteristic cold noodle soup texture.

6-Final Step: Cook the noodles according to package instructions until cooked and bouncy, then rinse under cold water multiple times and optionally add ice while rinsing for extra cold texture. Drain well. Portion noodles into bowls, pour chilled broth over them, and top with sliced beef, pickled radish, julienned cucumber, thin pear slices, and a halved hard boiled egg. Finish with toasted sesame seeds. Serve immediately, with extra mustard paste and vinegar on the side if you want more zing.