DIANA KENNEDY'S cookbooks are travelogues as much as recipe guides, so it was natural, when visiting Mexico, to take along her "The Cuisines of Mexico," in addition to the more obvious travel books. In fact, on the book's advice, we sidetracked to Puebla just to taste chiles en nogada , since we were in the middle of walnut season. Thieves broke into our car, however, theives so professional that they left two cameras but stole Kennedy's book.

Kennedy's work has not gone unnoticed in its own land.

Here are samples of the wisdom of Diana Kennedy, gathered from her demonstration at William-Sonoma and a few questions squeezed in the luncheon dialogue:

On Mexican restaurants in the U.S.:

"Mexican restaurants here now are where Chinese restaurants were 20 to 30 years ago with chop suey and chow mein."

On pumpkin-seed dip: "I think it is high time you threw out that awful cream cheese-onion soup dip. This should become your favorite dip." It does, however, look awful, "rather like the dog's dinner." But if it looks curdled, just throw it back in the blender.

On how to hull pumpkin seeds: "Use a recipe that calls for unhulled ones."

On cutting down consumption of fat: Tortilla chips can be toasted rather than fried, turning them into what Kennedy calls "diet crisps."

On cutting down saturated fat: Instead of substituting oil for lard in refried beans, "Use all the right things, but eat less. You want the calories to be good calories."

On chiles: Larger serrano chilies tend not to be as piquante as small ones. Never substitute canned chilies if the recipe calls for fresh or dry. "Every chili has a different flavor." The flavor is best released by toasting the chilies in an ungreased pan. In Yucatan, they describe flavoring a sauce with chilies as, "the chili should just take a walk through the sauce."

On electric appliances: "I do hope you haven't thrown your blender out." A food processor does not grind seeds as finely as a blender or small spice grinder. As for cooking on electric stoves, "I don't trust electricity. I hate silent heat." The Corning stove, though it is silly for cooking, is a wonderful tortilla maker; just cook the tortillas right on the glass surface. The microwave oven is very useful for reheating tortillas, stacked and covered in plastic wrap.

On buying tortillas: The tortillas in stores here are too yellow; their shelf life is too long. Tortillas should be mealy and not too thin. The answer to the problem of finding freshly made tortillas is to teach your children to make them.

On making tortillas: Use a heavy tortilla press lined with alligator-textured polyethylene bags. Put the ball of dough closer to the hinge than to the handle. Press, then peel the bag off the tortilla rather than the tortilla off the bag. The cast iron pan should be ungreased and hot enough that the tortilla sizzles as you put it in. Cook it fast so it doesn't toughen. When edges just start to dry, turn it over to cook, then turn once more. "No self-respecting cook of tortillas would turn them more than twice."

On serving tortillas: always keep them covered; it is bad manners to leave them uncovered. "And if you really know what you are doing, you never take the top one."

On tomatoes: Broil them "and get them nice and mushy" to bring out their flavor.At the end of summer, get a lot of tomatoes and broil them, then freeze them to use all winter.

On mixing ingredients: "Use your hands. You don't need to go messing up spoons."

On cooking shrimp: "You should never throw your shrimp peelings away." Poach them and freeze the strained broth to use for poaching other shrimp or fish. Do not overcook shrimp. Barely heat them until just opaque and still crisp.

On dried herbs: Some dried herbs, such as coriander, chervil and basil, "are not worth a damn." Dried tarragon and dill are fine.

On onions: Use white, not yellow onions for Mexican cooking, as yellow onions are too sweet.

On seasoning Mexican food: "People overdo things. There is too much cumin." Mexican food should be subtle. "Don't make your Mexican meal a fire-eating competition."

On what Mexican cooking has to teach U.S. cooking: "Texture, and not to rely on hunks of meat."

On the art of cooking: "The test of cooking is to make simple things delicious."