The tiny one-table terrace, spiffed up with flower-filled window boxes and a small vegetable garden, announces this unassuming neighborhood trattoria. Most of the friendly regulars start their meals with the namesake piadina—rustic flatbread filled with cheese, arugula or cured meat. Pastas also sport a homespun quality. We liked the spinach gnocchi in a light tomato-basil sauce and the garganelli with peas, ham and cream. The restaurant accepts only cash, but dinner for two (with wine) shouldn’t require much of it.