Milan and the Po valley, Lombardia — cassouela is the winter preparation of the entire Lombard plain. It is associated with Sant'Antonio Abate (January 17), the feast day of the pigs, when it is traditionally prepared. The preparation uses all the pork cuts from the seasonal pig slaughter.
Cassouela (from 'cazzuola', the trowel-like spatula used to stir it) is the Milanese winter feast preparation — a braise of pork ribs, salsiccia, ear, tail, and skin with Savoy cabbage (verza) that is cooked in stages: first the pork pieces are browned; the cabbage is partially wilted; then both are combined and braised for 2-3 hours until the pork has rendered its fat into the cabbage and the cabbage has absorbed the pork's flavour. The preparation is heavy, rich, and deeply savoury — a cucina povera preparation that uses every part of the pig alongside the winter cabbage. Traditionally eaten after the first frost of the season when the Savoy cabbage is sweetened by cold.
Cassouela in the bowl is dark and unctuous — the cabbage has completely absorbed the pork fat and taken on its colour and flavour; the pork ribs and sausages are tender and glossy. The flavour is intensely savoury, slightly sweet from the wilted Savoy cabbage, deeply porky from the multiple cuts. With soft polenta to absorb the sauce, it is the Milanese winter meal at its most satisfying.
Render diced cotenna (pork skin) in a dry pot until some fat is released. Add pork ribs and sausages; brown on all sides. Add carrot, celery, onion soffritto; cook until golden. Add white wine; deglaze. Add shredded Savoy cabbage in batches — it will wilt down significantly. Add a small amount of broth; braise covered 2-3 hours over very low heat. The cabbage should completely surrender to the pork fat; the preparation should be neither soupy nor dry. Season with salt and black pepper. Serve in deep bowls with polenta.
The Savoy cabbage (verza) improves dramatically after the first November frost — the cold converts starches to sugars and the leaves become sweeter. Traditional cassouela recipes specify post-frost verza. The pork components can be supplemented with pig's ear and tail (available from specialist butchers) for additional collagen and texture.
Insufficient cooking time — cassouela is a 2-3 hour preparation; under-cooked, the cabbage retains bitterness and the pork is not fully rendered. Adding too much liquid — the braise should be concentrated; the cabbage releases its own moisture; excess liquid produces a watery result. Missing the cotenna (pork skin) — the skin provides the gelatin that gives cassouela its characteristic sticky, unctuous quality.
Anna Gosetti della Salda, Le Ricette Regionali Italiane; Slow Food Editore, Lombardia in Cucina