If necessary, remove the fat from the ribs, rinse them, drain them and put them in a pan with one of the onions, the carrot and the stick of celery cut into large pieces. Season with salt, cover with water and cook over a low flame for at least two hours, skimming the surface from time to time.
When cooked, take out the ribs and set them to one side, keeping them hot. Filter the stock and bring it back to the boil. Peel the other onion, slice it finely and fry it gently, without browning it, in a pan with a knob of butter. Pour in the rice and allow it to absorb the flavour, stirring with a wooden spoon. Stirring all the time, add the stock a little at a time. Season with salt and add the remaining butter, grated cheese and a twist of freshly ground pepper. Spoon the risotto onto the plates, lay the ribs on top and serve.
Brodera was made in the rice-growing areas of Vercelli and Novara. It was prepared on the day the pig was butchered and traditionally accompanied by the still-warm blood of the animal, which was drizzled over the dish just before serving. This tradition has disappeared now due to the difficulty in obtaining blood and because tastes have changed.