Cassoeula Milanese di Maiale e Verza

Set a wide, heavy braising pot over a moderately high flame and, working in batches without added fat, lay the ribs, trotters, and tail sections flat in the dry pot, browning each piece on all sides until the fat has partially rendered and the surfaces are deep golden. Searing in a dry pot rather than in oil pulls the most flavour from the pork's own fat, and doing it in batches keeps the heat fierce enough to colour the meat rather than steam it. The pork should smell of rendered lard and toasted meat, not steam; remove each batch and set aside.

Discard all but a thin film of the rendered fat, reduce the heat to low, and add the butter; once it has melted into the fat, add the onion, celery, and carrot. Cook the soffritto slowly, stirring occasionally, until it is soft, pale gold, and without any raw edge — the onion should be fully translucent and the butter fragrant with cooked vegetable, because a soffritto that still tastes sharp will never sweeten properly once the braising liquid goes in.

Return all browned pork — ribs, trotters, and tail — to the pot, add just enough water to come halfway up the meat, and bring to a bare simmer. This is where the dish lives or dies: the heat must remain low enough that the trotters and tail release their gelatin slowly into the liquid, building the silky, unctuous braising sauce that will carry the cabbage — a rolling boil will tighten the meat and leave you with grey, dry flesh and a thin, greasy broth. The liquid should tremble, not bubble; after roughly one hour the trotters will begin to yield visibly at the skin.

Add the outer cabbage leaves, pressing them down into the braising liquid so they are wetted on all sides and begin to take on the fat and sweetness of the braise rather than simply wilting in steam. Cover and continue the gentle braise for 30 minutes. The outer leaves should soften and begin to collapse, taking on the colour of the cooking fat — a pale, translucent green-gold.

Nestle the cotechino or verzino whole among the pork parts, submerging it partially in the liquid, then lay the inner cabbage leaves on top and cover; adding the sausage at this late stage, rather than at the beginning, prevents it from splitting and losing its fat into the braise before the cabbage has had a chance to drink it in. Braise for a further 15 minutes. The cotechino should be heated through and firm to a gentle press — it must not split or go soft.

Remove the lid and stir in the splash of red wine vinegar, which cuts through the richness of the rendered fat and lifts the sweetness of the cabbage into focus without announcing itself as vinegar. Taste the braising liquid: it should be fat, sweet from the cabbage, and rounded by the vinegar. Serve directly from the pot onto white polenta, ladling the cooking liquid generously over each portion.