THE SLICE IS RIGHT

THE new season of chef Gordon Ramsay’s “Kitchen Nightmares” may premiere tomorrow night at 8 on Fox, but the bad-boy British chef won’t rest until his New York restaurants become prime-time hits, too.

“Every time I walk into the kitchen I’ve got my chef whites on and it’s serious. It’s like a boxer walking into the ring. You can’t come in second best. You always have to come out on top,” says Ramsay.

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Despite getting knocked down by critics when he opened his eponymous restaurant at The London NYC hotel in November 2006, the heavyweight chef is planning to get back in the ring with a more casual gastro-pub.

“In New York, I’m gonna do something a little bit more relaxed in the style of a cafe/bistro,” says Ramsay. “We opened Foxtrot Oscar in London – it’s an amazing neighborhood bistro along the lines of The Spotted Pig . . . It’s not because of the credit crunch or holding back. I just love that kind of alternative.”

The new strategy may be an example of the expert finally taking his own advice. On “Kitchen Nightmares,” Ramsay constantly admonishes restaurateurs to cater to local tastes and not let their own egos get in the way.

But when he opened at The London – his first New York restaurant -nearly two years ago, he took the exact opposite approach. The big-time chef with the big mouth picked the wrong neighborhood (a stodgy area of Midtown dead after dark); the wrong vibe (buttoned-up at a time when the city was casting off its starched whites); and the wrong food (French with fussy touches like bonbon trolleys).

Still, the potty-mouthed chef has proven resilient. Last fall, his restaurant at The London received two Michelin stars (Ramsay is now gunning for a third), making it an especially hot destination for tourists with euros to burn. And a recent visit found a sizable crowd – even in the doldrums of summer.

Of course, such issues may seem minor in comparison to those faced by the contestants on “Kitchen Nightmares,” in which Ramsay travels the country rehabilitating restaurants on the verge of collapse.

“I came across a situation on the East Coast where we had more roaches in the hot plate than customers in the dining room,” says Ramsay. “It’s frustrating because if that’s what it’s like when I’m there, what on earth was it like three weeks ago?”

It’s a thought to make any diner shudder. No wonder Ramsay warns: “Make sure you eat dinner before the program, please.”

This season, the hot-headed chef will visit failing restaurants in New York, LA, Chicago and Detroit in an expletive-ridden bid to save them. To create a sense of urgency – most of the restaurateurs on the show have everything to lose, including their families and homes – Ramsay curses, shouts and confronts. Because if Ramsay’s exacting standards have earned him a constellation of Michelin stars, it’s his colorful use of language that has made him a reality-TV success.

“[My language is] nothing I’m proud of. My mother’s certainly not proud of it. [But] can you imagine if in the middle of service [I said], ‘Please be so kind to pass me the spinach.’ F – – – it. ‘Move your ass. Give me the spinach. I’ve got to go now,’ ” he says.

Since the cameras are rolling, the chefs fight back. While filming the new season, an irate restaurateur chased Ramsay down the street with a knife. But once Ramsay breaks you down, he builds you back up.

“It’s the United States Marines. It’s a process that’s held true for years and years and Gordon’s phenomenal at it,” says Buddy Mazzio, owner of Finn McCool’s in Westhampton Beach, the recipient of a Ramsay rehab last season. “It’s like taking painting lessons from da Vinci. You pay attention to what he says.”

After Ramsay left Finn McCool’s, the Irish eatery hit a rough patch. The pub’s fried mozzarella sticks were gone, and so were its regulars. But the move from frozen to fresh eventually paid off.

“The reality is he was right,” says Mazzio. “We stayed the course. It was a little dreadful being the bill payer [because] it took a while for people to realize what we had become. And now it’s great.”

The results have been less dramatic at Midtown’s Purnima. Despite a transformative overhaul of its creepy-crawly basement and the arrival of talented Indian chef Vikas Khanna, the dining room still lacks customers. Of course, the scaffolding, noise and dust associated with a huge construction project next door certainly hasn’t helped.

This year, Ramsay isn’t just duking it out with critics, restaurateurs and roaches.

His latest competition: Chef Marco Pierre White, whose reality TV show “The Chopping Block” is coming to NBC.

Though Ramsay trained under White – another quick-tempered British chef who is credited with taking English cooking from pasty to palatable – the two chefs have been trading barbs in the British press for years, and their public feud recently landed on American shores. When White came to New York on a book tour last year, the blog Serious Eats reported that he called Ramsay “a liar, a thief and a huckster.”

But Ramsay thrives on the rivalry.

“After being slagged off so badly [by White] about being on TV and cooking at the same time five years ago, I find it fascinating that he’s now over here,” says Ramsay.

“I wish him all the best. I really hoped they’d have the balls to go up against ‘Kitchen Nightmares’ – but they’re not!”

Still, his knives are sharp and ready.

carla.spartos@nypost.com