I had a quick lunch in this super simple Trattoria right in the middle of the Market of San Lorenzo, you'll find it behind the curtains of the hundrends of colourfull stands, in the main street next to the right nave of the Church of San Lorenzo.
I know there is another Sergio, but on the other side of the river, I haven't tried it yet.
This place doesn't have a website, it is very casual, I'll put you the telephone number but I'm not sure they accept reservations...
They're quick, and even if you see it is super packed try to ask to the waiters how long you'll have to wait, they'll give you an idea.
The menu is written on a simple papershit, like the table cloth and the furniture in general, the service, everything is easygoing but the quality of the food is top high, and you have the chance to try the real tuscan trattoria.
I had a "braciola fritta con patate e pomodori" that means fried milanese cotoletta style, with tomatoes and fried potatoes - huge portion and excellent taste!
Da Sergio is open only for lunch, and it is closed on Sundays.
Trattoria da Gozzi Sergio
Since 1915 (wow!)
Piazza S. Lorenzo, 8r
Closed every evening and Sunday at lunch