Buta no Kakuni (豚の角煮) — Japanese Soy-Braised Pork Belly

• 600 gpork belly slab (skinless or skin-on, cut into 4 cm cubes)
• 1.8 lwater
• 2 inchfresh ginger (thinly sliced)
• 1Japanese long green onion (green top and white section, cut into 8 cm lengths)
• 240 mlsake
• 90 mlJapanese soy sauce
• 60 mlmirin
• 35 ggranulated sugar
• 4eggs
• 1 lcold water (for cooling boiled eggs)
• 200 gkomatsuna (trimmed)
• 5 gfine sea salt (for blanching greens)
• 2 tspkarashi mustard

Instructions

1. 1

   Cut the pork belly into neat 4 cm cubes, keeping the layers of fat and lean as intact as possible. Place the cubes in a heavy pot, add 1.8 l water, the 2 inch sliced ginger, and the Japanese long green onion, then bring slowly to a gentle boil over medium heat.

2. 2

   Reduce the heat to low and simmer the pork for 90 minutes, skimming foam and excess surface fat during the first 20 minutes. Keep the liquid at a quiet bubble rather than a rolling boil, because harsh boiling can toughen the lean layers before the collagen has softened.

3. 3

   Lift the pork pieces into a bowl and rinse them gently under warm running water to remove clinging scum. Strain and discard the pre-simmering liquid and aromatics, then wipe the pot clean so the final braising sauce tastes clear and glossy.

4. 4

   Return the pork to the pot with 240 ml sake and 500 ml water, then bring to a simmer for 20 minutes to let the sake mellow and penetrate the meat. Add the soy sauce, mirin, sugar, and the remaining 1 inch sliced ginger, then set a drop lid or a parchment circle directly on the surface.

5. 5

   Simmer the pork gently for 45 minutes, turning the cubes every 15 minutes so all sides become evenly lacquered. If the liquid reduces below one-third of the pork height before the meat is tender, add 60 ml hot water and continue at the same low heat.

6. 6

   While the pork braises, lower the eggs into boiling water and cook for 7 minutes for jammy centers or 9 minutes for firm centers. Transfer the eggs to 1 l cold water for 10 minutes, peel carefully, and keep them whole so they can absorb the braising liquid without breaking.

7. 7

   Bring a separate pot of water to a boil, add 5 g fine sea salt, and blanch the komatsuna for 45 seconds. Rinse under cold water, squeeze gently, and cut into 5 cm lengths so the greens stay bright and provide a clean contrast to the rich pork.

8. 8

   Add the peeled eggs to the pork pot for the final 15 minutes of cooking, turning them once so they stain evenly. Remove the drop lid and reduce the sauce for 5 to 10 minutes until it lightly coats a spoon and the pork looks shiny.

9. 9

   For the best texture, turn off the heat and rest the pork in its sauce for 20 minutes before serving. Arrange pork cubes, halved eggs, and komatsuna in shallow bowls, spoon over 30 ml sauce per serving, and serve with a small dab of karashi mustard.