China lays claim to the world's oldest hamburger, also known as a roujiamo, which dates back more than 2,000 years. You could dispute the use of the word "hamburger," but it's more fun to think of teenagers in ancient China wearing paper short-order-cook hats speedily filling orders at whatever passed for a drive-thru back then. At NBX, a chef-driven Chinese eatery with a short but intriguing menu of regional specialties from Shandong and Sichuan provinces (among others), the pace is more relaxed, and the Chinese hamburger (as it's called on the menu) takes the form of a housemade bun that's somewhere between a croissant and an English muffin, split and loaded with seasoned ground beef. It's a simple preparation, but the bun is light and delicate, and the meat holds layers of complex flavors.