By Heather Haddon | Photographs by Jennelle Fong for WSJ

IRVINE, Calif. -- A team at Taco Bell has been working, for nearly a decade, to invent a taco shell made entirely of cheese.

Its market research shows consumers are into the idea, and past inventions, like taco shells made from Doritos chips, were home runs that helped drive sales at the chain of around 7,500 U.S. restaurants.

It is on its fourth cheese supplier, and still is trying to figure out how to keep the cheese from disintegrating while the shell waits for fillings like ground beef and yet-more cheese.

"It softens up fast," Brett Pluskalowski, a Taco Bell product developer, told his boss, Liz Matthews, when she checked in one morning in July. "If you're talking about it as a crispy cheese taco, you've got to deliver crispy cheese."

Four months on, Taco Bell is still at work. Matthews, who is considered the best in the industry at coming up with new ideas, recently tasted the latest prototype. "Still work to do but I see it happening in the future," she says. "I think the team is getting close." Matthews wants to test it some more.

In the hypercompetitive world of fast food, Matthews is Taco Bell's chief food innovation officer and the master of a strategy so tricky to pull off that it has snarled up operations at rivals. She churns out, year after year, new items like cheese shells as limited time offers, or LTOs.

Chains need LTOs to keep their drive-through menu boards and apps popping with new items to keep customers coming back. The holy grail is a viral sensation online, and millions of dollars in sales.

McDonald's McRib had its first limited run in 1981 and still returns as an LTO. Starbucks turns the Pumpkin Spice Latte into a sign of the season each fall. This year Taco Bell and Matthews are on track to release around two dozen new menu items like a Flamin' Hot Grilled Cheese Burrito and Cheesy Street Chalupas, double last year's total. An item that takes years to develop typically stays on the menu for just four to six weeks.

LTOs need to be made largely with ingredients and equipment already in the restaurant's kitchen. Fast-food workers must be able to make them quickly and consistently. Starbucks struggled to quickly serve orders after its drink options grew increasingly complex. At Taco Bell, Matthews needs to maintain profit margins when much of the menu costs less than $5.

Taco Bell's same-store sales have grown annually since 2012, with the exception of a pandemic-driven 1% decrease in 2020 -- a feat few other restaurant companies can match. The chain is now the fourth largest by U.S. sales, surpassing Burger King and Wendy's. Earlier this month, Taco Bell reported a 7% increase in same-store sales at a time when many rivals' sales declined as consumers balk at $15 hamburgers.

Matthews understands that her inventions need to be what someone leaving a party on a Saturday night would crave, and she has an instinct for letting her team do radical new things without going too far. Her target customer is someone 18 to 30 years old whom Taco Bell calls a "cultural rebel," which it defines as a mindset. Put another way, an internal company executive profile heralded Matthews and other senior women as "the women behind the bro brand." In 26 years at Taco Bell, Matthews has helped develop sea-green Baja Blast soda, the Doritos Locos Tacos and the Crunchwrap Supreme, now Taco Bell staples.

"The reason she is the GOAT is because she understands the Taco Bell brand better than anyone and she is fearless," says Greg Creed, Taco Bell chief executive from 2011 to 2014 who promoted Matthews to chief innovation officer.

Taco Bell traces its roots to a menu experiment. In the early 1950s, San Bernardino, Calif., hamburger-stand owner Glen Bell noticed how popular tacos had become at rival restaurants, and started working on a fried, hard-shell version that was assembly line-friendly and easily eaten on the go. He experimented with seasonings, and in 1951 put a 19-cent taco on his menu.

There were naysayers, including his wife. "Why take a risk and make a radical change?" Bell wondered, according to the 1999 book "Taco Titan: The Glen Bell Story."

They would go on to divorce. Bell's tacos were a hit, and in 1962 he opened his first Taco Bell in a shopping center south of Los Angeles. The chain grew from there, and by the time Bell sold the company to PepsiCo in 1978 it had around 870 locations. PepsiCo spun off its restaurant chains in 1997, later called Yum Brands. Today Taco Bell's 8,800 global locations churn out roughly five million tacos daily.

Matthews grew up in Los Angeles eating Taco Bell Burrito Supremes, ordered with extra cheese and extra red sauce. (The flour tortilla with beef, refried beans, tomatoes, onions, lettuce, red sauce, sour cream and shredded cheddar remains her go-to order.) The youngest of four children, she was teased by her siblings for remembering family events for what they ate -- like the baked salmon at a wedding or mom's pizza. She waited tables as a teen and went to California State University at Long Beach with a plan to be a psychiatrist. After finding herself thinking more about ways to improve restaurant salads, she switched to food science.

She spent a few years working on pizza at Minnesota-based food company Schwan's, before making the jump in 1999 to Taco Bell as a junior product developer.

Matthews was assigned to work on developing a proprietary soda flavor. Taco Bell had discovered that customers were skipping drinks, and to sell more, it needed a beverage all its own.

She headed to PepsiCo's headquarters in Purchase, N.Y., for research and sampled sugary, caffeinated sodas for six hours straight.

"By two o'clock in the afternoon, they put me in a conference room," says Matthews of her subsequent caffeine crash. "They're like, you're going to need to just take a little nap."

Her work led to Taco Bell in 2004 introducing Baja Blast, a Mountain Dew variant sold only at Taco Bell. It has gone on to be a top seller. This month, as an LTO in some stores, Taco Bell is selling Baja Blast Pie, a neon green Key lime pie for "a Friendsgiving flex," it says.

A few years later Matthews tapped Pepsi IP again to develop another cult classic: a taco shell made of Doritos. Her challenge was to retain the chips' signature color without turning everything around the shell orange. The solution: a paper taco holster (Taco Bell's word for it) to separate Doritos-infused shells from others.

After two years of trial and error, Doritos Locos Tacos debuted in 2012, delivering hundreds of millions in sales in the first year and helping Taco Bell reverse a sales slump.

A year later, Creed, then-Taco Bell's CEO, wanted to shake up Taco Bell's innovation team. He set his sights on Matthews as his new chief innovation officer. She was several ranks below the role, and worried about taking on such a big job with two young children. Creed says he insisted.

"I figured at the end of the day, it was going to go really well, or it was going to go epically bad," Matthews said.

There were flubs, like when Taco Bell added butter to its rice in 2017. "I told Liz, 'I think we have a problem. My inbox is flooded with complaints,' " said Missy Schaaphok, one of Taco Bell's directors of global food innovation. Vegans were unhappy. Taco Bell nixed the butter.

Matthews worked on the 2015 launch of the chain's Cantina subbrand, which includes around 50 locations featuring late-night hours and booze. Its Las Vegas Strip location features spiked Twisted Freezes, and an in-house wedding chapel. Matthews was key in dreaming up the "Willy Wonka" touches, said S.G. Ellison, the restaurant's owner.

Matthews oversees a team of about 100 product developers who text each other ideas constantly. They scope out other restaurants and what people are ordering.

"It kind of consumes our lives," Matthews says.

Each year, Taco Bell tests hundreds of ideas in the Test Kitchen. Promising ones go before what the company calls "sensory panels" of consumers to taste test. About 40 ideas advance to restaurant testing. Matthews is ultimately the one who decides when to greenlight ideas -- or pull the plug.

Nearly 20 years after testing various french fries that never took off, Taco Bell started testing them in restaurants again in 2017. Matthews's team ran through 10 variations before settling on one coated in seasoning and dipped in nacho cheese sauce. For chicken nuggets, tortilla-based masa and jalapeño buttermilk coatings were the key. Taco Bell reintroduced nuggets to menus for a limited time earlier this year: five pieces and a dipping sauce for $3.99. Its limited-offer "nacho fries" are about $3.80 for a large with sauce.

On Matthews's morning in the lab this summer, developers were picking the right cheese combination for a quesadilla with poblano pepper and steak, which launched this past Thursday as an LTO. Other developers were experimenting with a sauce spray that could spread out flavors more evenly, and a new type of bowl for Taco Bell's pricier Cantina line, with slow-roasted chicken, corn and a fiery sauce.

"We call it skunking, right behind the scenes, just really figuring things out," said Matthews, as colleagues scrawled ideas for the crispy cheese taco on a white board. She encouraged them to keep going. "This is a fantastic idea," she said.

Write to Heather Haddon at heather.haddon@wsj.com

(END) Dow Jones Newswires

November 21, 2025 22:00 ET (03:00 GMT)

Copyright (c) 2025 Dow Jones & Company, Inc.