(FORTUNE Magazine) – Why is your local K mart passing out recipes for glaceed grapes and strawberries? Martha Stewart, 46, caterer to the rich and royal and author of books on entertaining, is cooking up trendy menu tips for the retailer's customers. As the store's ''home entertaining and lifestyle consultant,'' she will also help develop K mart products such as dishes and glassware. Sophisticated Stewart's joining commoner K mart is hardly a marriage gossip columnists would have predicted. But the reason for it is simple, says Walter F. Loeb, a security analyst with Morgan Stanley: ''K mart is changing the perception that it is a schlocky store that doesn't pay attention to fashions.'' Other merchants to the masses have used similar strategies. Sears Roebuck made agreements with designer Diane Von Furstenberg, golfer Arnold Palmer, and model Cheryl Tiegs to help create and promote products. J.C. Penney hooked up with Halston. The idea is to go upscale, but not too far. ''With Stewart we are really getting our whole new marketing program off the ground,'' says K mart vice president Michael Wellman. The company's challenge will be to refine its image while continuing to offer bargain basement prices. As for Stewart, she does not seem to care about losing snob appeal. She explains, ''K mart tells me I'm going to be as well known as Betty Crocker.''