My favorite Indian food is sabudana khichdi, a mild tapioca dish. When I visit my friend Nisha, who is from New Delhi, it's what I ask her to cook. She doesn't get why I wouldn't rather eat something celebratory, like meaty biriyani. Khichdi, she says, is for when your nose is so stuffed that you can't taste. But the way I see it, because the foods we eat when we're sick are so comforting, they're also some of the most enticing. From starchy grains to aromatic broths, what we turn to at our worst are also great when we're at our best. Every cuisine seems to have its own version.