While John Kunkel, mastermind behind the Lime Fresh chain, was building out his second location in 2005 at the Biscayne Commons shopping center in North Miami Beach, he ventured into Oishi Thai next door.

Owned by chef Piyarat Potha Arreeratn, former sous chef at South Beach’s Nobu, the place had just opened and already had a reputation for being a cut above. Kunkel, who spent three years in Southeast Asia in his 20s learning an ancient form of Thai boxing, quickly became a regular.

“The food was excellent, but it was the American version of Thai food, basically the southern Thai style heavy on the coconut curries,” says Kunkel. “But one day I stumbled in around 4 or 5 p.m. when the staff was about to sit down for family meal, and for themselves they had made some very traditional northern Thai dishes. That was the food I wanted and couldn’t find anywhere.”

Arreeratn, better known as Chef Bee, is from the northern Chaing Rai region of Thailand, but figured his South Florida clientele wanted familiar fare. Kunkel, meanwhile, had always wanted a restaurant that served the rustic northern Thai dishes he had fallen in love with: the sour pork, the kaffir lime, the hot chiles, the Burmese, Laotian and Vietnamese influenced dishes.

Fast forward to December, when he opened Khong River House just off Lincoln Road in the old Miss Yip space with Chef Bee as executive chef. It’s the second post-Lime Fresh venture for Kunkel, who in 2011 opened the successful Yardbird Southern Table & Bar and in April sold his fast-casual Mexican chain to Ruby Tuesday’s for $24 million.

“When we started working on the project, we flew in a couple of chefs from New York who really understood the kind of Thai food we wanted to serve. But then we had Chef Bee come in and cook for our team, and he blew everyone else away,” Kunkel says.

Khong, which bills itself as an “approachable fine dining” spot, is designed to evoke the boating culture and farmhouses along the Mekong River. Wall paneling is repurposed Thai shipping pallets, bare Edison light bulbs dangle from electric cords, and the weathered ceiling is of corrugated tin.

Servers are regularly quizzed about the not-so-familiar menu. Go ahead, about the gai yaang, or rotisserie chicken, marinated for two days in coconut milk and stuffed with lemon grass, turmeric, garlic and coriander seeds. Or the gang hang laey muu, pork belly with chile paste, lemon grass, turmeric, garlic and palm sugar in a pickled garlic and tamarind broth. Ask about the kha muu pa low, whole pork leg braised in herbs, spices and oyster sauce, served with chile vinegar and fresh steamed buns.

“This cuisine is a language, history and geography lesson,” Kunkel says. “This restaurant tells a story. When servers go out with a dish, we ask them to repeat the name, to be able to explain something about it.”

His Southeast Asian sojourn in the early 1990s “100 percent helped shape the kind of adult I would become,” the 41-year-old says.

“I was 6 feet tall, 185 pounds, fighting as a light-heavyweight, and here comes a little guy, 5-2, who just wallops me. Most of my teachers were half my size. For an aggressive young American guy, it was a great humbling experience. It makes you reset your ego.”

Thailand immediately got under Kunkel’s skin, and he has returned many times.