Soak pork neck bones in cold water for about an hour to draw out any blood, then drain the water.

In a large pot, add the pork bones, cover with water, add a splash of mirin, and parboil for about 10 minutes.

Drain the parboiled pork and rinse each bone under running water to remove any impurities.

Return the clean pork bones to the pot. Add chopped onion, garlic cloves, dried chili peppers, salt, and enough water to cover everything.

Cover the pot and let it simmer for about 45 minutes.

Add aged pogi kimchi to the pot.

Season with gochugaru (Korean chili flakes), minced garlic, and soup soy sauce.

Cover and simmer for another 45 minutes until the pork is fall-off-the-bone tender.

Just before serving, add sliced tofu and chopped scallions.

Cut the kimchi into bite-sized pieces using kitchen shears and serve hot.