Japanese Kakuni Pork Belly and Buta No Kakuni Braising

Ingredients

• 1 kg pork belly, skin-on, with even alternating layers of fat and lean; cut into 5–8 cm squares
• 200 ml sake
• 200 ml mirin
• 100 ml soy sauce, added in the final third of cooking only
• 30 g sugar
• 500 ml dashi, as the braising base
• 3 slices fresh ginger
• 3 green onion tops
• 1 tsp karashi (Japanese yellow mustard), to serve alongside

Method

1. 1
   Place the pork belly squares in a pot of cold water, bring to a boil, and cook for 5 minutes. Drain, then rinse each piece thoroughly under cold running water, removing all coagulated proteins and myoglobin from the surface. The water must run clear before proceeding.
2. 2
   Heat a heavy pan over high heat. Sear the blanched pork belly squares briefly on all sides until a pale Maillard crust forms. The surface should colour without burning — a subtle caramelised depth, not a charred exterior.
3. 3
   Transfer the seared pork to a wide, heavy braising pot. Add the dashi, sake, and mirin. Add the ginger slices and green onion tops. Bring to just below a simmer — 90°C maximum. Place an otoshibuta (drop lid) directly on the surface of the pork and liquid. Maintain this gentle heat for 60–75 minutes. The liquid must barely tremble; no rolling boil. This is where the dish lives or dies: sustained low heat converts collagen to gelatin and renders the fat to trembling softness — any temperature above a gentle simmer will contract the protein fibres irreversibly, and no subsequent cooking will correct that toughness.
4. 4
   Add the soy sauce and sugar. Continue braising under the drop lid at the same low heat for a further 30–45 minutes. The pork is ready to glaze when a skewer meets no resistance passing through the lean layers and the fat yields entirely to the touch.
5. 5
   Remove the drop lid. Increase heat slightly and baste the pork periodically with the braising liquid as it reduces. Continue until the liquid forms a glossy, lightly coating glaze — it should sheet from a spoon, not fall in thick viscous drops. The surface of each piece will appear lacquered.
6. 6
   Remove from heat. Leave the kakuni to rest in the braising liquid, uncovered, for 30 minutes. The pieces will absorb the seasoning as the temperature equalises; the exterior will deepen in colour and uniformity. Smell the pot: the aroma should be sweet-savoury with no raw pork note remaining.
7. 7
   Lift each piece carefully and plate. Strain the spent braising liquid and reserve for other uses. Serve each portion with karashi on the side, blanched greens, and steamed rice.