For an awesome take away lunch near Madison Square Park and the Flatiron, try Baoguette (61 Lexington between 25th and 26th). It’s worth the walk. They serve incredibly fresh Banh Mi sandwiches, and earn 4 stars from Yelpers. There is a pork banh mi, a bbq chicken one, a catfish one that gets rave reviews, and a spicy curry beef.
The pork sandwich comes with bbq pork, fresh cilantro, pickled carrots and daikon radish, cucumber, ham, and a touch of pork liver pate, all on a fresh baguette. If you ask for it spicy, it packs a punch with some fresh jalepenos.