When you open a large glossy cookbook, you don't expect to see photographs of young chefs folding napkins, spraying each other with water, scrubbing floors on all fours, taking heavy trays of scraps to the recycling bins, ironing tablecloths while they're on the table, slurping spaghetti from bowls, foraging for fallen olives, spooning down ice-cream and generally enjoying some downtime.

Yet the Swedish photographer Per-Anders Jorgensen's stunning new oeuvre does just that.

It's intended to shine a light on the hidden side of the job: the hard graft (or "brute hard work", as the author describes it) that goes into running one-star, two-star and three-star Michelin restaurants. Aside from the mundane tasks, what we're also seeing is staff members preparing their own daily staff meal - something not many of us are aware of, yet it's crucial to the smooth-running of the kitchen. Jorgensen's series of 200 affectionate and offbeat photographs gives readers a glimpse of the all-important sense of unity experienced by all staff members, from kitchen porters to head chefs to front-of-house servers and glass polishers - and it looks like great fun. To make us readers feel we're part of it, there are recipes to make at home.

The staff meal, or family meal as it's often referred to in the trade, has multiple roles. It is essential for morale and for promoting a sense of belonging, which is vital for creating the right atmosphere front of house. (I once sat with the staff, including Michel Roux Jr and senior sous-chef Monica Galetti, at Le Gavroche in London's Mayfair to share their 5pm meal of roast chicken legs and spaghetti with fresh tomato sauce. It was simple and delicious, and the banter was great.) In southern Europe, it's eaten round the table like a big extended family; in other parts of the world it's more often than not eaten standing up. "No matter," writes Jorgensen. "Wherever the family meal is deeply rooted in the culture of the restaurant, you find a business that is thriving and a staff who are happy."

At Noma, the world's No1 restaurant in Copenhagen, there are lots of stagiaires (interns) from all over the world, so the staff meal is a way of showcasing the food of their home country. Consequently, says Jorgensen, they understand each other better and are more powerful as a team. At Il Canto, Siena, Italy, the head chef insists on cooking the staff meal himself to show his appreciation of his team; as a result he believes they work with added passion. At Le Chateaubriand in Paris, someone will simply open the walk-in refrigerator and cook with what's available. In other kitchens, each member of staff gets a chance to cook.

The point of the shared staff meal is that it creates friendly rivalry and a sense of pride which, Jorgensen says, is a positive energy that ripples out to the dining room. It is what makes a good restaurant great. He predicts it won't be long until the casual, family-style meal moves out of professional kitchens to become the theme of the restaurants themselves.

So what do they actually eat? Jorgensen describes it as good, rustic, traditional food - the type so many chefs strive to deliver to customers, and that customers now want to cook at home. At Alice Waters's Chez Panisse in California, it's a three-course outdoor meal at 8.30pm after first sitting, where everyone discusses the menu, the food, art and politics. Everyone feels they belong as they tuck into summer vegetable soup with pesto, squab torte and champagne jelly. At Anne-Sophie Pic's Maison Pic in Valence, France - the only three-starred Michelin restaurant in France with a female head chef - it's chicken liver salad, roast chicken with apple and onion confit followed by chocolate mousse (see panel) for 100 staff in a special dining area. At Thomas Keller's French Laundry in California, staff get cafeteria-type compartmentalised trays ("prison plates") filled with modern American regional food like pulled-pork buns, meatball sandwiches, fried chicken or rice pudding - the antithesis to fine-dining food but prepared with incredible care, skill and attention to detail.

Fergus Henderson's St John in London is one of the few places where staff eat the same as the diners. "The philosophy of using every part of the animal runs so deep that staff have to be comfortable with it," he says. As cheaper cuts are viewed as a delicacy, it's seen as a perk of the job to eat them: so there is no fear of fat or offal or marrowbone. Every day at 11am and 5pm, staff sit down to get stuck into devilled kidneys with mash, slices of ox heart with thick hand-cut chips, bread soaked in the rendered fat of a hunk of pork. That way, all staff, from all parts of the world, get to experience "the essence of no-nonsense Britishness" - exactly what you get in the dining room.

It's interesting to note that while modern cooking has become a serious art, it's also increasingly instinctive. This is the case with the kitchen "family meal" and also when cooking at home. As the author's interviews testify, "The act of cooking should be free-form and open-ended, a journey as much as a destination."

Eating With The Chefs: Family Meals From The World's Most Creative Restaurants by Pers-Anders Jorgenson is published by Phaidon, priced £39.95.