Friggione (also known as frizòn) is an onion and tomato dip, a traditional peasant dish originating from the farming villages around Bologna. It is prepared by macerating thinly sliced white onions in salt and sugar and then slowly cooking them in lard with the addition of chopped fresh tomatoes.
Nowadays, the lard in recipes is often replaced with extra-virgin olive oil, but the onions remain an undisputed star of this dish: not any sort will do, and as the onions need to be sweet and delicate, the perfect choice is a famous local onion variety called medicina.