A Master Class, in Secret

- The dessert provided an understanding of the delicacy of airy, egg-foam-based concoctions. Plus, who doesn't like chocolate mousse?

Richard never condescends to his audience members, no matter their ages. The lessons were rigorous, to be sure, but within the capabilities of his pupils.

Well within.

The elder sister, Elizabeth, attends Holton-Arms School and is a writer, a pianist and a self-proclaimed bookworm and cheese freak. (On her hand, she had written "Books + cheese = life.") Her younger sister, Julia, is no less accomplished; she studies at the Potomac School, is a gifted painter and plays the cello. Incidentally, their father, Steve Rosenbaum, is a partner in the law firm of Covington & Burling; their mother, Hae-Soon Hahn, was a professional violinist.

When Richard arrived at noon on teaching day, Hahn offered him something to drink. (She knew her audience, too. She had prepared a lavish snack buffet that included a two-pound box of Godiva chocolates.) "Glass of champagne!" the chef boomed, snapping his fingers imperiously. The girls and their mother stared at him incredulously. "Non, non, just water," he continued, grinning mischievously. The girls giggled, Hahn heaved a sigh of relief, and Richard helped himself to some chocolates.

"Okay. Let's get to work. First we're going to make the gougeres."

And they were off. The lesson was completely interactive. Richard performed only the tasks the girls were not yet familiar with, such as cutting vegetables and folding egg whites properly. To keep things moving, he alternated instructions between the two sisters, who scurried to keep up: "Set the oven to 325. Bring me a saucepan. Get a stick of butter. . . ."

When the butter, milk and water came to a boil, Richard had Julia put the flour in the pot. He whisked it into a paste, then beat in one egg. "You beat it until you can't see the egg anymore," he explained as he handed over the whisk for the girls to add the remaining four eggs. When the dough was finished, he piped one small mound onto a baking sheet as a model and relinquished the job to Elizabeth and Julia, correcting their technique along the way until they got the hang of it. Once the puffs were in the oven, Richard issued an order he would repeat throughout the day like a mantra:

"Clean! Clean! It is very important to keep the kitchen clean!"

Then he started the bouillabaisse. He showed the girls the French method of turning a whole artichoke into eight pieces trimmed neatly into hearts, a technique with which many accomplished home cooks are not familiar. As they took to that and every task of the day, Richard lavished them with encouragement.

"Good job! Good job! Parfait! The artichoke was the hardest part. The rest is easy," he assured.

"So basically, the soup is the most complicated dish," Julia said. She was hooked, and Richard lit up.