Leaning forward with his elbows propped on the dining table, chef de cuisine Vatche Benguian exudes good cheer and the sense he’s seen it all in the kitchen.

A veteran of several local high-profile kitchens — including La Colline, Gerard’s Place and the opening of Blue Duck Tavern, as well as working along with D.C.’s legendary Jean-Louis Palladin, who taught him about making his own vinegars and about using lemon oil — Benguian now takes on the job of cooking for the hugely popular Roof Terrace Restaurant. Think Sunday brunch, when about 300 people line up for the buffet line in its vast kitchen, and you understand the challenge.