French Onion Flatbread
CHEF: TOM CARLIN
RESTAURANTS: GLADSTONE TAVERN, GLADSTONE • THE CASSIDY BAR + KITCHEN, MAPLEWOOD
Chef Tom Carlin is ambivalent about the French onion soup served in most restaurants. “Usually they’re not that good, but I do like them,” says the chef-owner of Gladstone Tavern and Cassidy Bar + Kitchen. “I can’t say that I’ve ever had one that blew me away. It’s just that there’s something about it that I know I like—and I know other people like.”
His French Onion Flatbread reinterprets this classic comfort food by rearranging its addictive combination of deeply browned onions, rich veal stock, toasted bread and melted Gruyère.
“When people have French onion soup, what they really want is that crust and the onions and the cheese—all kind of baked and caramelized,” Carlin says. “That is a flatbread version of it. Caramelized onion, sherry and broth with melted Gruyère hits some kind of primal instinct.”
Slowly browned onions are the centerpiece of this dish. To cook them properly, Carlin says, use a wide, short-sided stainless steel pan with a thick bottom to prevent hot spots where the onions might burn. Begin with a one-inch-thick layer of onions—don’t crowd the pan more than that because then your onions will steam rather than brown. Once the moisture has been driven off and the onions begin to color, stir frequently to achieve uniform browning and prevent scorching. The goal is a medium-dark brown, which should take about 20 to 30 minutes.
Once the desired color is reached, the onions are seasoned with salt and pepper. “The seasoning has to be just right,” Carlin says. “Add salt and pepper at the beginning, on the lighter side. But make sure that you leave a little room to finish at the end because you definitely don’t want it overly salty. When it is almost done, taste and adjust.”
Noting that deeply flavorful broth is the secret to great French onion soup, Carlin next adds sherry and veal demi-glace, which he makes using a three-day process that transforms roasted veal bones and vegetables into a thick, rich base that can be used for a wide range of dishes. Home cooks can purchase veal demi-glace or substitute beef stock—although that sacrifices some of the richness found in veal stock.
To assemble the dish, Carlin rolls pizza dough out into an oval—a shape he chose both for ease of preparation and rustic appeal. The onions are spread over the dough and topped with Gruyère cheese. After baking, the flatbread is brightened with a spritz of high-quality sherry—a trick he learned while working at Gotham Bar and Grill. “Alfred Portale always did that,” Carlin says. “He would make a sauce with sherry in it, but at the very end he would always add raw sherry to pick it back up.”
The flatbread is topped with a seasonal garnish of lightly dressed celery root salad, which cuts the richness of the dish. “We were trying to think, what goes well with this rich French onion soup flavor? It’s celery,” Carlin says. “I love celery. It is bright and fresh tasting and crunchy.”
Carlin also experimented with adding short ribs to the flatbread topping. “It was too much—a little too rich. It just didn’t need it,” Carlin says. “French Onion Flatbread is more of a finger food than a meal. It’s great bar food, and I just want to keep it a little bit lighter.”
273 Main St., Gladstone
THE CASSIDY BAR + KITCHEN
160 Maplewood Ave., Maplewood