Classic Ribollita

|A big fat soup that's the very essence of kitchen economy|carrots cavolo nero celery|2 onions peeled roughly chopped2 carrots roughly chopped3 cloves garlic peeled roughly chopped3 ribs of celery roughly chopped2 tablespoon olive oil400g chopped tinned tomatoes250g cooked canellini beans2 bay leaves4 slices of thick bread2 cup cavolo nero choppedsalt and pepper|Cook the onions carrots garlic and celery in a deep pan with olive oil for 20 minutes until soft.Stir in the tomatoes and canellini beans with 250ml of their cooking water and add bay leaves. Leave to simmer over a low to moderate heat for 30 minutes.Tear up the bread and dunk into soup.Stir in the kale and season to taste.Simmer for another 15 to 20minutes until you have a thickish soup adding more bean water if necessary.Serve in bowls with a trickle of olive oil.|10.00 minutes|4|The Guardian