The Sterns, authors of Roadfood and other guides to American eateries, proclaim the focus of their book to be ""recipes that epitomize colloquial cuisine, the meals ordinary people used to cook."" They have researched this repertory by way of many an ancient Pillsbury brochure, teen-cuisine guide, and bride's vademecum along with the odd present-day Iowa cafe--their declared aim being to rescue good honest food from oblivion, with only a very occasional oddity ""more compelling as an amusing cultural artifact than as dinner."" In fact, there is hardly a source or tradition that they do not chortle and posture over. Just what, in the context of cookery, is squareness? Well, that's part of the problem. The Sterns certainly take it to include a lot of robust, unpretentious food, much of it lumped together in a chapter called ""Sunday Dinner,"" and unnecessarily squarified with recipe titles like ""Mom's Best Pot Roast"" and ""Best Cook in Town Spoon Bread."" But then there is ""Nursery Food,"" a let's-regress fantasy that takes in anything juvenile from chicken noodle soup and tapioca pudding to Banana Rice in ""a gooey, golden blanket of cheese"" or Gumdrop Pudding. ""The Cuisine of Suburbia"" is a prolonged wallow in the joys of Lipton dips, patio luaus, and things like chicken baked in lemonade concentrate. The pity is that a genuinely charming and valuable book could have been constructed from the same materials that furnished this exasperating exercise in kitsch.