Just as Thomas Edison stumbled through useless prototypes of light bulbs and movie cameras before perfecting the phonograph, the alchemists at Qdoba Mexican Grill took 47 attempts before landing on the franchise's signature blend of three cheeses, known simply as queso. That attention to detail still pervades every aspect of the menu, as employees spend hours each day chopping, dicing, and simmering the fresh ingredients that find their way into burritos, taco salads, and grilled quesadillas. Beyond the marinated bites of chicken, beef, and pork and hand-crafted tortillas, cooks protect their ripe, fragile avocados from harm by smashing them into batches of fluffy guacamole.