In the mood for some chili? You're gonna need three cups of onion, medium dice. Making chicken stock? Two onions, large chunks, please. And what about onion soup? Yes, believe it or not, you'll need onions for that too. No matter how you slice 'em, onions are used in a good 30 to 40 percent of any cook's savory dish repertoire, if not more. They are the first thing you should learn how to cut when you pick up a knife, and, at least for me, are still one of the most pleasurable foods to take a sharp blade to. In this slideshow, we'll go step-by-step through all of the basic onion cuts, as well as talking about the differences between various flavors of onions.