Unfortunately I only have 1 day in Bologna on my way back from Puglia. I will be arriving early in the morning on an overnight train, and then leaving on another overnight train from Bologna to France. I intend to leave my luggage at the station and walk around all day, punctuating the visit with at least 2 delicious meals I hope. Any recommendations on sights not to be missed and trattorias open on Sundays at lunch and/or dinner? I'll be on a budget, so ideally I wouldn't want to spend more than 15 to 25 euros for a meal if possible. (at lunch I probably won't have wine since it makes me sleepy, but for dinner I'll definitely want plenty to help me sleep on the train ;)
Grazie in advance for your advice!