Potato-leek soup

Made with just potatoes, leeks, and chicken broth, this hearty potage has all the robust taste of the traditional one made with cream­—but none of the fat. To clean the leeks, trim the roots, leaving the root ends intact to hold the layers together. Slice them lengthwise, fan open the layers, and swish them in a large bowl of cool water. Let them stand a few minutes to allow the grit to fall to the bottom, then lift them out. This soup can be completely or partially puréed and served hot or cold. (If you serve it cold, label it “vichyssoise,” as sophisticated chefs did in the sixties.) For even more convenience, it can be refrigerated for up to three days.