Bruce Johnson has received numerous requests from his British customers over the years, asking him to teach them how to make his famous fish and chips. On vacation to the US, one English patron, who owned several UK-based restaurants, even offered Johnson free airfare and a two-month trip across the pond in exchange for lessons on how to perfect the dish.

“They’ve asked for my recipe, but I won’t give it up. I just can’t do that,” said Johnson, who has worked as the head chef at San Mateo’s famous The Swingin’ Door pub for the last 40 years. “I had one [British] guy offers me $5,000 for the batter recipe.”

Known as the ‘fish man,’ Johnson has created a robust menu out of a deceptively small kitchen at The Swingin’ Door — previously named the Prince of Wales — transforming its menu from a few bar food fixtures to a long list of chicken, burgers and, especially, seafood variations over the past four decades. The most notable change took place in the 1980s while his boss was out of town. Johnson took the opportunity to experiment with a new fish and chips recipe, swapping out a different type of cod and tinkering with the batter. The change was an instant success.

“[The owner] goes, ‘We’ll go ahead and change the recipe, but next time you don’t do that again. You discuss it with me,’” he said. “I thought I was going to get fired.”

But perhaps what’s most impressive is that Johnson has never even set foot in England. In fact, he was born and raised in a place most would consider the exact opposite. The Hawaii native grew up eating fish only when it was uncooked, and his culinary endeavors initially involved his own take on island classics, such as the teriyaki chicken recipe he perfected while working alongside his co-workers at a pineapple factory during his adolescence.

“Some of the girls at the factory were making it on the hibachi one night, and I started watching how they were making their sauces and stuff,” Johnson said.

The job solidified his penchant for cooking, which continued growing throughout high school, especially after excelling in a home economics class that he originally signed up for as an easy elective. During high school events, he’d even serve huli huli chicken, another Hawaiian staple, which became a hit among his classmates, and his teachers encouraged him to pursue a culinary career. After graduating, he worked at several establishments, including hotels and restaurants, eventually working his way up to management positions.

Such a trajectory was not what his family envisioned, however, nor was it what Johnson originally planned for. His uncle, who raised him alongside his aunt, worked in law enforcement, and many of his other relatives also worked in the field as well, some worked as border patrol agents and others as police officers. It was expected that Johnson would also enroll in the police academy after graduating, just like his cousins.

But by the time he was around 13, he started having doubts about pursuing such a path, especially after overhearing one particular conversation between his uncle and aunt over a drunk driving incident.

“There was a child involved that died, and he was just growing up. I could hear him telling my aunt, ‘I can’t deal with this.’ “That’s when things started changing in my mind, like, maybe I don’t want to go into law enforcement,” he said. “I thought, well, everyone has a need to eat, and if I can cook well, then at least I’ll always have a job.”

Fast-forward almost six decades later, and the nearly 70-year-old San Mateo resident doesn’t have any what-ifs about his career. Feeding people and knowing they’re enjoying his food is why he’s stuck around for so long, and his self-taught, trial-and-error approach to some of his most popular dishes has served him well.

“I have a lot of fun with the customers, and I guess that’s why I’m still here. It’s not just the cooking. It’s the clientele that comes in here. They’re very appreciative towards me,” Johnson said. “It makes me feel good that I have a place I can call my second home.”

But, much to their dismay, Johnson recently announced his retirement, which will start in June. While he’ll miss the events and traditions that made his tenure so memorable — darts competitions, cook-offs, Christmas caroling — he’s also looking forward to giving his body a much-needed rest. The manual nature of such a job can be exhilarating, but it also has a price tag, he said.

“My doctors are telling me, my wife’s telling me. It’s time to hang it up,” Johnson said, though, he added he’d still help with ordering or filling in as needed.

As for the rest of his spare time, it may consist of a visit back to his home state — which would be his first in about 20 years — not to mention more time spent with family.

“I might go back to Hawaii because my sister lives on the big island, and my nieces and nephews run hotels over there,” he said. “And there’s things around the house my wife wants me to get done.”