When I eat this dish, I am immediately transported back to when I was a boy, sitting at my grandmother Nonna Mary’s table. Passatelli is one of those dishes that is inextricably tied to the place whence it comes. Romagna (the eastern part of Emilia-Romagna, where my parents were born) is still the only place you’ll find this soup. The name literally means “passed through.” Dough is pushed, or passed, through a tool that consists of a perforated disk attached to two handles, forming a wormlike shape. You’ll only find the tool in Romagna, but a potato ricer is an excellent substitute. Since the broth is an integral part of the soup, I would strongly encourage you to use homemade broth, which is something I always try to have on hand in our freezer. Passatelli are often made with grated lemon zest, which is the way my mother makes them. Personally, I prefer them without, as I find the lemon flavor takes away from the heartwarming earthiness of the dish. I’ve included it here as an optional ingredient, so you can decide for yourself.