The Shiitake Pie at Co. (bread man Jim Lahey's Chelsea pizzeria) is an unusual little number, with a walnut and caramelized onion spread forming the base for shiitake mushrooms. But one bite and you'll find that the tastes and textures of this cheeseless pie are supremely harmonious. The sweet onions and rich, nutty walnuts come together to form something similar in texture to ricotta. Top that with rosemary, bold, smokey shiitake mushrooms (or try it with Hen of the Woods), and herbaceous branch lettuce and you've got yourself one make-at-home-worthy pizza. Just click through the slideshow to find out how!