Mercado Central de Florence
For the best lunch in Florence I recommend visiting the Mercardo Central de Florencia, it's full of locals and tourists, but here you can browse around and select exactly what local goodies you'd like to try.
Here you have the opportunity to get up close to the chefs & their personal and ask them all the food questions that other city restaurant waiters don't know or not interested in.
Relaxing and comfortable seating make it perfect for grazing between the food stalls and pop up restaurants.
Writing the next menu is easier if you're in such an inspirational place, a great market always does it for me. Fresh local seasonal produce at its best. zucchini focaccia is a big local winner, but stealing the idea is no guarantee for success in another country.
I don't think anyone will disagree that Italian has fantastic produce and food culture, if your'e looking for something different you'll need to look hard there aren't many international options available, local pride is ever dominant.
Italy abounds with cafes and great coffee, local pick me up sweets aren't far away, they look great and some taste as good as they look, others you know that you can get the same dessert of better quality in 200 different cities around the world, 1/2 fabricated frozen produce abounds everywhere so don'y be disillusioned. It almost makes you wonder how they can be so protective and allow their quality and ambition to slip unnoticed