At 3:30 on a cloudy spring afternoon, Seamus Mullen – then the executive chef and partner of Boqueria, a trendy Spanish restaurant in New York City – was in the kitchen prepping for the evening rush. His first task: dissecting the carcass of a freshly killed 35-pound lamb.

“My hands are hurting today,” he said. That and a slight limp were the only hints that this talented, up-and-coming chef with Irish good looks was diagnosed with rheumatoid arthritis (RA) a few years ago. A bolt out of the blue – he has no family history of the disease – it turned his world upside down but fueled his determination to continue doing what he loves.

With the precision and patience of a surgeon, he used two knives, a Japanese meat cleaver and a saw to separate the lamb, gently placing each part – the rack, neck, shoulders, and so on – to the side. By midnight, when the restaurant closed, he had worked 12 hours, though too often he works 15.

Seamus’ trademark offerings are tapas, tiny snacks that are standard fare in Spanish bars. But they’re a far cry from American bar foods. Think marinated olives and cheese, cured sausage, fresh seafood and produce, dates, savory herbs and spices and antibiotic- and hormone-free lamb.

His cooking has wowed finicky food critics. One crowed that Seamus can “cook his butt off and still decorate a plate prettily and poetically like an artist.” With praise like that, it’s no surprise Seamus is rising to the top ranks of chefdom; in February  2010 he was named a semi-finalist for the title “Best Chef: New York City,” by the prestigious James Beard Foundation. In 2009 he was among a dozen chefs vying for the title “The Next Iron Chef” on the Food Network show of the same name. (He was eliminated halfway through.)

It’s heady stuff for a guy who grew up in Vermont, learning organic farming from his grandmother.

His love affair with Spanish food began in high school when he spent his senior year abroad. He studied Spanish language and literature in college and returned to Spain for his junior and senior years.

After graduation, he trained with top chefs in California, New York and Spain and worked as a sous chef in New York City until launching the first Boqueria – there are two locations now – in 2006.

A New Challenge

In April 2007, as he was savoring his success, RA changed everything. After sporadic bouts of pain that landed him in the emergency room – and one bout at home that was so severe he was unable to phone for help (a neighbor heard his cries seven hours later) – he was diagnosed. “I was scared,” he says. “I wondered, ‘How much longer am I going to be able to work?’ I still feel the sky could fall at any moment. That’s the scary thing about this disease.” He has no plans to hang up his apron, and he tries his best not to let RA interfere with his work.

But during one stressful episode of “The Next Iron Chef,” Seamus experienced a flare so severe that he was wheelchair-bound between scenes. “The producers didn’t know I had RA until it became apparent,” he says. “I thought if I could do the show, it would be an incredible accomplishment for me and an inspiration to others with RA.”