Everything on the Taco Time menu has the Tonkin family seal of approval.

It’s been that way for 50 years, starting when the taco was pronounced “tayco” in Renton.

This year marks the 50th anniversary of the family owned Taco Time Northwest, which has grown into an iconic chain of 73 Mexican restaurants that in the last 10 years has sold enough of its signature Mexi-Fries to circle the globe.

“What a beautiful thought,” said Robby Tonkin, great-grandson of founder Frank Tonkin Sr., who opened his first Taco Time in 1962 in White Center.

Today, Robby Tonkin and his cousin Chris Tonkin run Taco Time Northwest, the fourth generation of the Tonkin family to do so.

Robby, 33, has a law degree from the University of Washington and Chris, 26, a business degree from the UW. Taco Time isn’t big on corporate titles, but when the big boss stops by a Taco Time for an inspection or a taco, it’s Robby or Chris or both.

They meet regularly with their grandfather, Frank Tonkin Jr., 79, who goes by Jim. He started out as a bus boy at Tonkin’s Cafe owned by his father on Third Avenue South at age 6, when he could barely carry a tray full of dirty dishes.

“I came by it naturally, the restaurant business,” he said.

The Tonkin family has been in Renton for nearly 130 years, operating a general store downtown through the early decades of the 1900s, branching out to restaurants, a men’s clothing store and eventually, Taco Time.

Jim Tonkin’s sons, Bob (Robby’s father) and Matt (Chris’s father), followed in their father’s footsteps in running Taco Time.

After graduating from Renton High School, Jim Tonkin went on to Washington State University to study home economics, one of two men in the program.

He married “the girl of my dreams” and started a family, working with his brothers-in-law on their family orchard in Eastern Washington, growing apples, pears and cherries. In 1962 his father Frank came for a visit, with an invitation to check out his Taco Time restaurant.

“I took the first bite of a taco that I’ve had, period, and I was sold,” he said. He packed up his family and moved to West Seattle.

He worked side by side with his father Frank to build Taco Time in Western Washington, which includes company-owned and franchise restaurants. There are two Taco Time Northwest restaurants in Eastern Washington, in Moses Lake and Wenatchee.

In 1979 the Tonkins ended a long-time franchise relationship with the Taco Time company based in Eugene, Ore., and incorporated as Accord Inc. to franchise restaurants in Western Washington. Other Taco Times in Eastern Washington and in Oregon are part of that other corporation, now based in Arizona.

Today, Robby and Chris Tonkin are taking Taco Time into the future, mindful of their family’s promise to their customers to use fresh ingredients in all their meals and to buy much of them from family owned companies locally and throughout the Northwest.

The corporation has had decades-long relationship with Petschl’s Quality Meats of Tukwila, which provides Taco Time with Northwest-grown beef, and with La Mexicana of White Center, which provides fresh-baked tortillas.

Mexi-Fries are now made from potatoes grown in Washington, not Idaho.

Robby and Chris certainly know the Taco Time routine.

Robby at a very early age spent his days in a crib or playpen in the back of the Taco Time in Totem Lake in Kirkland. They’ve both worked in the family business, in high school and during the summers off from school.

Want to give Chris directions? Start from the nearest Taco Time.

Chris’s mom Gayle gets credit for the white chicken chili, a “Fit-Hits” meal under 200 calories by the cup.

“I used to have white chili long before we were serving it at Taco Time,” Chris said.

The cousins can’t think of anyone who has veto power over what to put on the menu. It’s a group decision.

Taco Time doesn’t have a research and development department other than the Tonkin family itself and long-time employee Colin Ury does much of the test cooking.

Chris’s Taco Time favorite is either the crisp taco or the soft chicken burrito. For Robby it’s the chicken natural soft taco and crisp tacos.

Robby will take his kids to McDonald’s. “It’s good research to see what’s going on.” His kids “love Taco Time,” too, with a Mexi-Fries and the chicken nuggets especially for kids on their favorites list.

Taco Time is marking its 50th anniversary with new initiatives, some involving food and some involving its restaurant operations.

“We want to be here for another 50 years and more,” said Robby. “We are introducing these initiatives as a launching pad into the future.”

Taco Time often will test-market new menu items for a short time – even just hours or days – one of its restaurants in Renton and  nearby. Taco Time devotees have already had a chance to try out the sweet potato Mexi-Fries, which Chris said have been a big hit.

Rather than doing surveys, Taco Time relies on daily customer feedback and observations from restaurant staff to get a sense of how well its doing with its service and its food.

The Taco Time Traveler, a new taco food truck, will make its way to about 50 events around the state this summer to hand out food starting around July 1.

Maybe not as noticeable to the taste buds at least is Taco Time’s compostable packaging that will mostly end up at Cedar Grove Composting in Maple Valley, rather than in a landfill. The green initiative is “really easy” for customers, who will dump plates, utensils and cups into a composting bin, Robby said.

James Tonkin, Chris and Robby’s great-great grandfather, came to Renton in 1884 from England. He opened Tonkin’s General Store, which stood where Tonkin Park on Williams Avenue is today. The park is home to the runaway coal-mine donkey.

His son, Frank Tonkin Sr., worked in the store with his brothers. Frank branched out into the restaurant business, opening the Tonkin’s Cafe in 1933 on South Third Street.

In the early years most everything on the menu was priced under a $1. A grilled King salmon steak with a lemon, served with potatoes and toast, was 85 cents.

Long-time residents will remember Bif’s, a fast-food hamburger restaurant at the corner of Rainier Avenue and South Second Street, which Frank Tonkin opened a in 1958, just four years before he started to build his Taco Time empire. Bif’s became a Taco Time in 1964.

The Tonkin family doesn’t release financial information about Taco Time, which is privately held. The company has about 1,500 employees.

But Robby Tonkin talks about the company’s core values of fresh ingredients and service to customers. Those values date back to his great-grandfather, Frank Tonkin Sr., who also had a commitment to care for his employees, Robby said.

In the end, it’s always about the food.

“We don’t confine ourselves to a quick-service or fast-good box,” Robby said. “We try to prepare, develop and serve the highest quality food we can.”