Thomas Keller: Master class - latimes.com Perfecting the egg By Thomas Keller, Special to the Los Angeles Times The real test of a chef doesn't come from elaborate dishes with luxury ingredients such as foie gras and caviar but from how well he uses the most humble foods in the pantry. Consider the egg. I'm fascinated by seemingly simple dishes like an omelet or a crème caramel because they not only showcase the quality of their ingredients, but, more important, they also demonstrate the skill of the cook who prepared them. Indeed, it's only through repeatedly preparing these dishes - striving to do better each and every time - that a cook can begin to understand their complexity, and then master them. The omelet is a perfect example. Granted, there are numerous ways to both prepare and enjoy an omelet, but what I consider to be a perfect omelet - a yellow, uniform exterior without browning or air pockets and a creamy, just-cooked interior - is a test of skill that requires an understanding of the fundamentals of cooking and a measure of patience, both in developing one's craft and in the act of cooking itself. When I first began to work in the kitchen, I was taught to make omelets using very hot pans with generous quantities of oil. Omelets made this way were impressive to behold, at least for the cook in the kitchen. They would soufflé and take on the look of puffy yellow pillows. But by the time they reached a guest in the dining room they would have fallen and have nothing to show for their rapid cooking besides an uneven, brown-spotted exterior. I first encountered what I consider to be a perfect omelet during my time as a stagier in France. There I found the soft-centered, bright yellow omelets prepared in local bistros to be the ultimate after-work meal. To this day I still think of omelets less as a breakfast food than as a perfect late-night treat. To make a perfect omelet, the egg yolks and whites must be mixed to a completely uniform state. After years of vigorous whisking, I finally hit upon the blender as the easiest and most efficient way to do this. Then, rather than frying the omelet over high heat, I cook it very slowly. This is what creates a perfect creamy texture, without tough spots or air holes. Another dish that showcases the egg - and the cook's mastery of technique - is the old-fashioned crème caramel dessert. I first learned to make this classic custard under Pierre Latuberne at the Café du Parc in Florida and later refined my technique by repeatedly preparing them at La Rive in New York's Hudson Valley. To this day I still consider the quality of a crème caramel to be a good indicator of a pastry chef's skills. Again, the main point is cooking the eggs slowly to create a rich, silky texture. When making a crème caramel, you do this by baking it in a bain-marie - a roasting pan filled halfway with water to moderate the oven's harsh heat. Such a delicate dish can't be poked or probed while cooking, so it is up to the cook to judge the mobility of the custard when it is gently jiggled in the pan to determine doneness. Too little time and the custard will not maintain its beautiful shape when turned out onto the plate. Too much time and it will be tough, possibly even curdled. Practice will teach you when it's perfect. Additionally, time is a key ingredient in any custard. Plan ahead so you can let the custard rest in the refrigerator before and after cooking so that its flavors fully develop. It's more work, but for those willing to invest the time and attention, the ideal result is among my favorite desserts: rich, creamy and, of course, full of eggs. Because so many egg dishes are quite simple, the cook has to rely on the quality of the eggs used to make the finished dish great. Until recently eggs were largely treated as a uniform commodity, but, like so much in the culinary world, thanks to today's artisan producers we now have a phenomenal variety of eggs to work with. In dishes where delicacy is desired, we use the tiny eggs of quails. When we want an extra depth of richness (and the season is right), we use duck eggs in place of chicken. Even with chicken eggs, we have a great variety to choose from. Sometimes we like to showcase the intense flavor of Jidori hen eggs or the pale blue shells of eggs laid by Ameraucana hens. The skills that lead to a great egg dish are the same that will make you an all-around better cook: an appreciation for the central importance of quality ingredients, an understanding of the vital interplay of time and temperature, and the patience and finesse required to properly prepare such a delicate food. Remember that good cooking is merely a matter of understanding these basics and being able to apply them to several tasks simultaneously. Do not be daunted, but instead enjoy the road to mastery and take pleasure in the simple joy of repetition. Keller is the chef and owner of Per Se in New York and the French Laundry in Yountville, Calif., both of which have earned three Michelin stars.