Zuppa di lenticchie e cavolo nero
celery • carrot • leek • small potato • Tuscan kale leaves (about 50 grams), stems removed • dried lentils (about 70 grams) • bay leaf • extra virgin olive oil • vegetable broth (about 600 ml) or water • tomato puree (about 50 ml) • Salt, to taste • Freshly ground black pepper, to taste •