Catapulting himself from leadership positions at Taco Bell and Pizza Hut parent Yum! Brands to Chipotle, Niccol is no stranger to fast food. Since beginning his CEO tenure at Chipotle in 2018, he’s spearheaded the Mexican-inspired chain’s massive turnaround, helping it shed its E. coli crisis and embrace a new identity as a culinary-forward fast-casual empire, even setting the lofty goal of doubling its restaurant count to over 7,000 locations in the U.S.

Starbucks needs the boost that Niccol gave Chipotle. As the coffee chain’s fourth CEO in just two years, Niccol will inherit an ailing empire that has struggled to romance inflation-fatigued customers. Amid sales dips and customers abandoning online orders due to congested stores, Starbucks is also contending with pressure from investors to install sturdy management. CFO Rachel Ruggeri will fill Narasimhan’s shoes as interim CEO until Niccol’s takeover on Sept. 9.

Luckily for Starbucks, Niccol, a 30-year retail food veteran, is used to taking over fixer-uppers.

The mash-up master

Mexican-style fast food was a comfort zone for Niccol, who held the CEO role at Yum! Brands’ Taco Bell from 2015 to 2018 before his stint at Chipotle. It was there that he helped Frankenstein Taco Bell’s now-mainstay Doritos Locos Tacos, as well as its limited-time Cap’n Crunch doughnut hole mashup. He also masterminded the chain’s “Live Más” ad campaign and pioneered its mobile ordering app.

But before becoming the architect of Taco Bell’s viral creations, Niccol was an engineering major at Miami University. He happened to take a marketing class that piqued his interest more than his initial engineering track. Niccol piled on economics and business credits before he graduated in 1996 and joined Procter & Gamble as a brand manager of Scope mouthwash, then assistant marketing director.

After nearly a decade at the company, Niccol left for Yum! Brands in 2005, where he rose from the rank of vice president to chief marketing officer of Pizza Hut and Taco Bell to eventually lead the Mexican-inspired chain.

Chipotle’s transformation

By the time Niccol transitioned to his role as Chipotle’s CEO in 2018, the fast-casual chain was beleaguered by the fallout from an E. coli outbreak that hospitalized 20 customers. As if the crisis weren’t enough of a stomach ache, Chipotle’s reputation hit was compounded by defensive marketing campaigns about its food safety practices and piled-on discounts and promotions. Niccol redirected the company’s efforts, ditching its promotions and showing restraint in refusing to participate in the Breakfast Wars where fast-food chains were exerting so many resources to expand menus and hours.

Instead, Niccol encouraged a culinary-forward approach to Chipotle. He helped educate store staff on the seasonality of ingredients and emphasized the chef-like role of the chain’s line workers and the theater of customers watching them prepare foods. Chipotle pivoted to online ordering and has experimented with automation and limited-time novelties like garlic guajillo steak and chicken al pastor that harken back to Niccol’s time at Taco Bell.

While Niccol will leave Chipotle in better shape than he inherited it, the chain will continue to contend with sensitive customers, who have made known their concerns about the amount of food and consistency of portion sizes as the restaurant’s prices continue to tick upward.

“We always want to give people big portions that get them excited about the food,” he told Fortune this spring. “If you want to double the amount of meat, you gotta pay for it, but our goal is to get people really excited about what I believe is really delicious food.”