Minestra sporca, traditional Brescian soup

A traditional Brescian soup usually served before spit-roasted meat and polenta. I make it in winter without the roast too: humble but very flavoursome.
INGREDIENTS
STOCK
1/2 CHICKEN
1 CARROT
1 CELERY STALK
1 ONION
2 LITRES WATER
SALT
I first make chicken stock by boiling half a chicken with carrot, celery, onion, a little salt and 2 litres water for about an hour and a half. Here I use only stock. The meat made chicken salad with pickled Lombard peppers and Leerdammer; the chicken main courses section has other ways to use boiled or roast chicken leftovers.SOUP
1 PACK CHICKEN LIVERS AND HEARTS
1 CARROT
1 CELERY STALK
HALF AN ONION
EXTRA VIRGIN OLIVE OIL
1 PIECE BUTTER
SALT
PEPPER
SMALL SOUP PASTA
GRATED GRANA PADANO
I wash livers and remove impurities and fatty parts.I finely chop them.I wash vegetables.I chop finely. I put in a pan with extra virgin olive oil and butter.I sauté a few minutes.I add livers.I cook gently about twenty minutes and add salt and pepper.I add chicken stock.I simmer about ten more minutes, add soup pasta and cook until done.I serve with grated Grana Padano.