The abusive chef Gordon Ramsay and lots of sharp knives close at hand are the two ingredients that give “Hell’s Kitchen” its flavor.

So, on the eve of tomorrow night’s season finale, we talked to young chefs who have been on the show before, crew members and people who have eaten in the show’s famous dining room.

We wanted to know what you don’t see on the pressure-cooker series — the behind-the-scenes stuff that makes the series sizzle.

What we found is that the stress of “Hell’s Kitchen” is real — but maybe the food is not.

Diners see and hear everything: “It is almost like dinner theater,” Season 6 contestant Robert Hesse warns. “People go there to hear Gordon curse and cause drama.

“There is only plate glass on two sides of the kitchen, and that is to keep people from the dining room out. But I have been on set when diners have walked right into the kitchen. They want their five seconds of fame.”

It’s not a real restaurant: The kitchen and dining room are actually on a soundstage in Culver City, Calif. Guests can request seats by signing up on the show’s Web site.

“But they make you sign something that says you are not guaranteed to eat anything,” Hesse says.

The bar is open: “The food was OK, but not great. And the service was really slow — we were there for like three hours,” says viewer Joseph Contreras, who scored a seat in the dining room in early 2009.

“The best part is they give you all the free beer and wine and bread you want.”

Chef Ramsay is well protected: “He has a few Suge Knight-looking [guys] waiting to break some necks,” Hesse says.

“If you saw the episode where the military guy snapped [and challenged Ramsey to a fight in the parking lot], those are his bodyguards. They are ready for anything.”

Cameras are everywhere: “The ones you don’t see are behind mirrors,” Season 6 contestant Seth Levin tells The Post.

“They are directly behind either side of the kitchen.” And in the dining room? “Each diner is going to be filmed. They also have a ground crew inside the dining room while service is going on that goes table to table and has people asking questions about the food.”

No do-overs: “There are never re-shoots. Filming is continuous,” Hesse says.

“The producers have a plan of what they want to do — the destinations, the characters. But basically Ramsay is a bees’ nest, and they throw it in a room, shake it up and see who gets stung.”

Goodbye, cruel world: Computers, personal electronics and phones are strictly off limits to contestants. “It is just you by yourself in LA in this pit of fire,” Levin says of the five-week filming cycle.

“There was one time that one of us got a hold of a newspaper, and it was like all hell broke loose. They came over and ripped it out of our hand!”

Post-show rehab: Each contestant eliminated from “Hell’s Kitchen” is immediately taken for a psychiatric evaluation.

“The experience can be quite draining, so [the producers] want to make sure you don’t want to kill yourself — or someone else,” an on-set source reveals.

“After that, they send you to this beautiful house where you can get anything you want: back rubs, nails done, hair cut. It is kind of like decompression before you go back into society.”

Contestants have to eat elsewhere: “They give you about an hour to run up to your own kitchen in the dorm at night,” says Levin. “You can throw a sandwich together real quick, eat it and get back down for dinner service.

“They kind of want to drain you and make you crazy. And they do a good job of it!”