It's said this dish was invented ten years ago, after a pho restaurant ran out of broth. Whether that's true or not, in the past few years phở cuốn has become very popular in Hanoi, especially in the area around Truc Bach lake, where it is said to be invented. Although, the ingredients are similar, the rolls taste much different than the soup. Thick sheets of rice noodle are used as a sort of tortilla. Thin slices of beef are marinated with garlic, salt, sugar, pepper, and fish sauce then sauteed -- sometimes with mustard greens. The rice noodle sheets are filled with the beef, some herbs and vegetables that you'd also find in the soup, and maybe some lettuce and scallions. They're rolled up and piled on a plate, ready to be dipped into a sweetened fish sauce. These are delicious. It won't be long before a plateful is devoured.