1️⃣ Blanch the bones
Add bones to a large stockpot (8 quarts or larger). Cover with cold water. Bring to a boil over high heat, then reduce to medium and boil for 5 minutes.

2️⃣ Drain + clean
Drain the bones, rinse them thoroughly, and clean the pot to remove any residue. Return the bones to the pot.

3️⃣ Long simmer for milky broth
Refill with cold water until bones are submerged with about 2 inches of water above. Bring to a boil, reduce to medium, cover, and simmer for 6–9 hours (or longer if possible). Maintain a gentle but steady boil. Add water once or twice to keep bones submerged.

4️⃣ Cook the meat
Add the brisket or shank during the last 2–3 hours of broth cooking (add enough water to fully submerge the meat if needed). Bring the broth back to a gentle boil, then immediately reduce to a steady simmer. Cook until fork-tender but still sliceable, about 2–3 hours, depending on thickness. Remove the meat, cool slightly, then thinly slice against the grain, cut into cubes, or simply shred with your hands. Keep the meat in a container until ready to serve.

5️⃣ Strain & save the good stuff
Remove bones and strain broth into a clean pot or bowl. Don’t discard the collagen and elastin around the bones—pick them off and add them to the meat.

6️⃣ Chill & defat (optional)
Use a fat separator or refrigerate overnight until the fat solidifies and can be spooned off.

7️⃣ Reheat broth & season
Bring the broth back to a gentle boil. Season with salt and pepper, tasting as you go.

8️⃣ Assemble & serve
Add cooked rice or noodles to bowls, then top with beef and chopped scallions. Ladle the hot broth over everything. Add kimchi to the bowl right before eating or serve it on the side to enjoy with the soup. Add blanched bok choy or spinach if desired.