Also, Louis Lunch, particularly if you mom hadn’t been there. It’s been there since everyone on earth was born, and claims to be the inventor of the hamburger. Kind of like the Soup Nazi on Seinfeld, but for hamburgers. “No ketchup, or buns for you.”
And if you want to see a thriving international cuisine food-cart/truck culture go to the Whale or York Street by the hospital at lunch time.