In a shophouse in Battambang this week, Khmer-American Ry Mam has a burger on the gas stove when the power cuts. He leaves the meat sizzling as he checks the situation down the block. He quickly returns, and apologises through the kitchen window.

“I’m the only one running the place in the afternoons,” he says.

That’s likely because Ry’s Kitchen is a pretty simple operation. It started last year with a Cuban sandwich cart he stationed a few streets over. Six months ago, he moved it into a brick-and-mortar shop adjacent to a guesthouse, where he serves up good – and greasy – specialties from the place he called home for 32 years, with his own twist.

Mam, who is 40, was deported from the US six years ago. Born in Cambodia, he and his family left as refugees. Though he had lived most of his life in California, he spent some time in prison, and was notified that his permanent residency in the US would be revoked in 2005 under the extradition agreement between the two countries.

The long-awaited call came in 2010. Mam was apprehensive: he had no memory of Cambodia. “I was like, ‘I have to wait for a few days, I have things I have to tie up, you know?’” he says. “When I got here, it was a huge culture shock.”

Mam travelled to Battambang province, where his father had grown up and where some of his family remained. He is not alone in Cambodia’s northwest. Since 2002, when the agreement was signed, 536 Khmer-Americans have returned to Cambodia after serving time. Mam estimates there could be a few hundred in Battambang city alone. After all, he points out, many refugee families originated there.

And the city to which he returned is where he eventually found his calling.

“I started establishing my connections the first day I got to Battambang,” he says. “When you come to Battambang, someone always knows someone.”

Even though he had a network, Mam didn’t initially feel at home, something he sees in the rest of the Khmer-American community.

“People can feel lost when they get here,” he says. “I was lost for two years, I can tell you that. Once [someone] gets here, he wants to know other returnees that come here.”

For Mam, staking out a life in Cambodia has become tied up in his food. For a while, he lived off of his savings and bided his time, but he knew he needed a project.

“I had to work through the things I was going through on my own,” he says. “I had to find something.”

A friend suggested he start making sandwiches. In the US, Mam says, he had only worked for others. In Cambodia, he found his creative streak.

“With the food cart, I really started getting into it,” he says.

When he didn’t feel the Cubans were up to par, he started making his own mayonnaise and pickles.

House specials at Ry’s Kitchen now include Mam’s original Cuban sandwich ($3), served with a choice of meat; a variation on Canadian poutine ($3.50), with beef and mushrooms piled on the gravy; and a thick buffalo burger ($4.50), topped with cheese and home-made sauce.

But he’s also started cooking some Khmer food – American-style. “In America, the Khmers cook Khmer food totally different from here,” he says. “For lok lak, they use the Asian ingredients, but they add dabs of mayonnaise. It’s actually pretty good.”

Ry’s Kitchen opened only in April, but it’s already attracted attention; this month, his story and his sandwiches were featured on Vice, along with his prominent tattoos. Mam says they often give away his identity: “Well, my tattoos, stuff like that: automatically [Cambodians] tell me, ‘That’s no good.’ But I say, ‘You guys know me. Am I no good?’”

It’s a principle reflected in his restaurant, the only American-style greasy spoon hidden amidst Battambang’s sleepy streets. Luckily for residents and visitors, it, like Mam, is likely to stick around.

Ry’s Kitchen is located next to Ganesha Guesthouse, Road 1.5, Battambang. Open daily, 7am to 10pm.