Make polenta with 2 l of water and salt to taste.
Cook for 45 minutes.
In the meantime, sauté onion, celery, garlic and diced tomatoes for about 10 min. Remove the casing from the sausages and add to the sauce, cook at low heat for 15 min. Salt to taste and add some basil just before completely cooked.
Pour the polenta on a wooden board, make a well in the centre, pour in the sauce and serve piping hot.