Arancine al ragù

Make the ragù. Warm the oil in a heavy pan and cook the onion, carrot and celery gently for 10 minutes until soft. Add the mince and brown it, breaking it up. Pour in the wine and let it bubble away, then stir in the tomato purée and passata with 200 ml (¾ cup) of water. Cover and simmer gently for 1 hour, stirring now and then, until thick. Add the peas for the last 10 minutes and season. It must be thick enough to hold on a spoon. Cool completely.