I'm not sure if you were thinking about a pizza instead of a drink, but there is a pizza called margherita at Via Napoli.
Wood fired Authetic Pizza Napoletana - Margherita. Tomato, mozzarella, basil. Indivdual 16.00, large 28.00 1/2 meter 39.00 - $28.00
We haven't been yet, so I don't know how good it is. Plan on going in September.