As the name implies, two ingredients create a world of possibilities at this always-packed Mission hot spot. Neapolitan pizzas and handmade pastas (like al dente garganelli with whole-grain mustard and braised pork) will have you sighing after each bite, and a selection of more traditional mains (such as seared duck breast with chanterelles and pecorino-dusted charred Brussels sprouts) score every bit as big as the noodles and pies. Laid-back service, up-to-the-moment music and a buzzy, effervescent vibe make flour + water the epitome of California cool. Throw in a glass of their refined Italian wine, along with an alluring dessert like the salted caramel apple tart, and you can see why getting a table here is well worth the challenge.