There is a burger revolution afoot in Istanbul. Fast food restaurants and diners serving high quality beef burgers are cropping up all over the city. There’s Dükkan Burger (the fast food version of the Dükkan steakhouse chain), Burger Bar, and numnum. I visited the Maçka branch of the latter last night with my friend Susan and we were bowled over by the food: the onion strings, cheeseburgers, and fries lived up to, even surpassed, our expectations of an American burger experience. Now Mehmet will you please expand your numnum empire to Rome?