Asked if there were seconds at state dinners, Mesnier was equally decisive. "No, there are no seconds and no doggy bags."
But Comerford contradicted him with a smile: "We have never denied a guest."
"That's new," Mesnier said.
One thing the chefs agreed on: For state dinners, there is no room for error. You have to get it right, every time, on time.
"This is not the time to cry or call 911 or call your mother," Mesnier said. "You don't get a second chance."
Usually, making and timing all of the dishes in advance -- a routine practice taken so the first lady and staff can sample them and make final choices -- eliminates any chance for error.
Still, Mesnier came close to disaster once, he said. He was making hot raspberry souffles for a large state dinner serving 250. The egg whites wouldn't whip. He started over twice, dumping out both batches. And then he overheard the chef and sous chef talking about mayonnaise they had made that morning ...
It takes only three drops of residual oil to sabotage egg whites, the chef explained.
Turning to a clean bowl, he started again, this time to success. To speed up the cooking process, the souffles were started on top of the stove and then put in the oven at the highest heat possible, he said.
"We were ready just in time, down to the second," Mesnier recalled. "I still have nightmares about it."
Questions about "first children" brought smiles and more stories.
Amy Carter would make cookies, Ruta said.
"She'd make a mess," Mesnier chimed in. "She'd put them in the oven and then go off and roller skate."
Chelsea Clinton did indeed come down to the White House kitchen for cooking lessons before she left for college.
But when it came to the Obama girls, Yosses and Comerford were resolutely closemouthed, following the family's wishes. Yosses would say only that "the girls come down once in a while."
Mesnier recalled that once he was called at home at midnight to return to the White House to bake and decorate a birthday cake for Chelsea, by then a college student at Stanford, and box it up special for her parents' early-morning flight. He did it without complaint.
Said Mesnier: "You have to be fully dedicated if you work for the White House."