Tried-and-true recipes from the noted Southern food expert, hostess of her own TV cooking show, and Louisiana State University home demonstration agent.   These kitchen-tested recipes, reflecting the savory dishes for which the Deep South is noted, will have strong appeal for the sophisticated cook and the beginner as well. Collected and refined during the author's long career as a Louisiana State University home demonstration agent, these more than 700 recipes will provide the basis for countless hours of cooking and dining pleasure.   Included are sections dealing with the preparation of gumbos and soups, breads, poultry, meats, seafood, rice, vegetables, salads, pastries, candies, jellies, jams, and preserves. Also presented are the author's special salad secrets, a complete section on the preparation of party foods, and surefire instructions on how to brew a perfect pot of coffee.