The Flavorful Mushrooms Bobby Flay Uses For His French Dip Sandwich

French dips are an icon of the sandwich-loving community. They're warm and toasty, hearty and savory, comforting and nostalgic, and ideal for a cold day — or just about any other, for that matter. And yet somehow, despite their simple perfection, there are culinary minds who find ways to make major improvements to this classic with little twists — and Bobby Flay is one of them.

Instead of going with a standard issue au jus, the celebrity chef, TV host, and cookbook author amps up his liquid with a very particular mushroom variety: porcini. In an episode of his hit Food Network show "Beat Bobby Flay," he explained his plan to the audience and the rationale behind going rogue with this ingredient addition. "Porcini mushrooms are very earthy," he told the camera. "They'll just elevate the flavor of the beef."

For his broth, Flay started with a beef stock, then added onion, garlic, and rosemary, along with dried porcini mushrooms. After cooking this combination together, he blended and strained it, then served it alongside his sandwich.

In general, Bobby Flay adhered more or less to the French dip formula (which originally is a proud creation of California, not Europe) to go with this porcini-spiked dip, but found even more little ways to elevate his sandwich. He used a different spread for each side of the interior — a mustard and horseradish mixed with mayo on one, and a garlic butter on the other. Gruyere may be one of the underrated cheeses you should mix into your mac and cheese, but Flay found another home for it here, topping his thin sliced beef and giving a nutty flavor to his sandwich. He also toasted it up with olive oil, salt, and pepper so that every bite would be complete with a satisfying crunch.

Yet with all the flourishes, Flay was adamant that the porcini mushrooms were the critical component. "This could be my secret weapon," he said of the fungus. So even if you know all the best French dips you can find in America, making this professionally-inspired rendition right at home will ensure that you can satisfy a sandwich craving any time.