There's a version of a well-stocked kitchen that costs a fortune — specialty oils, imported cheeses, fresh herbs that wilt before you use them. And then there's the version that actually works: a core set of inexpensive, long-lasting staples that make it possible to throw together a real meal on any given Tuesday night without a last-minute grocery run. The families who consistently spend less at the grocery store aren't eating worse. They've just figured out which ingredient