KAPLAN, La. HERE in the land of drive-through daiquiri joints and truck-stop casinos, you often eat better in grocery stores, butcher shops and cafes than you do in restaurants. There are exceptions, of course, but in Acadiana, as a rule, the more rudimentary the surroundings, the more genuine the grub. Bare bulbs, in other words, are what you look for, not recessed lighting, paper napkins, not linen. Another thing: the best Cajun cooking isn't blisteringly hot, contrary to popular belief. It's not about incinerating fish and meat. The guardians of regional tradition produce rich, slowly simmered soups and stews, more...