Umbria is known for its tiny green lentils, cultivated near the towns of Castelluccio, Sostino, Colfiorito, and Sellano. This recipe is from Salvatore Denaro, the esteemed proprietor of Il Bacco Felice, an enoteca in the town of Foligno. He uses water rather than stock so that the special taste of the local lentils shines, and he ladles the soup over toasted bread. The classic lentil soup of the Madonie, the mountainous region of central Sicily, includes chopped toma