'YOU got a time on these potatoes for the café?" head chef Andy Cumming asks of one of his sous-chefs in the downstairs kitchen at Rogano.

The reply is lost in the hubbub, but Cumming has already switched his attention to the latest order relayed from the upstairs restaurant.

"Two scallops, one venison, one pheasant!" he calls out. It's the second last Saturday before Christmas, a hugely popular night for office parties, and, given that Rogano, this venerable, 78-year-old, Art Deco-imbued restaurant, has one of the busiest kitchens in the city, it is going to be a demanding night.

Which it is, eventually. The weather, early on at least, is December-raw, which means that everyone in Glasgow wants a taxi, which in turn means delays for those diners arriving here to take their pre-booked tables. At one point the restaurant chefs are caught in a lull; you can almost see them bracing themselves for the impending rush. One 14-strong office party has simply failed to show; Rogano tried to phone them, got no reply, and so, with a shrug, assigned their table to other diners. The deposit, of course, was lost.

It's fascinating to watch a kitchen like this one at work. The abiding sense is one of focused calm; everyone knows what he or she has to do. Cumming, a man of 28 years' hard-earned experience, likes to draw a football analogy, with his team flexibly moving forward or back as the orders come in, with the seasoned commis chefs as the midfield.

Cumming, of course, is the team captain. He hand-picks promising youngsters for his team, and he has been involved with Rogano since 1987: despite a number of spells elsewhere, he keeps coming back.

As he calls out fresh orders - "Two starter scallops, one Cullen skink, two fish of the day, one fillet steak" - his sous chefs, Gordon and John Paul, move with practised, unflustered ease.

On one side of them is the cooking equipment: a six-ring gas hob in constant operation, an oven, a huge griddle pan, an eye-level grill, a frier for Rogano's chunky chips, and an electric induction capable of bringing a pan to the boil in 25 seconds.

On the other side is the area where food is plated before making its way sideways towards the pass, where Cumming casts his eye over every restaurant-bound dish, adding final little flourishes where appropriate. The plates are then transferred to a stainless steel hoist that rises to the restaurant. It can take up to four minutes for the food to reach the table, so speed is of the essence.

Two large pork bellies, cooked earlier that day, lie cling-filmed, ready to be sliced and served with today's fish of the day, John Dory ("they go well together", Cumming tells The Herald at one point. At another, carrying a large slab of beef over his shoulder, he remarks: "For a seafood restaurant, we sell a lot of beef at this time of year.")

Another order. "Five starter scallops, one dressed crab, two sea bass, one main salmon, one venison, one fillet steak rare, one fillet steak well done." They are starting to flow now but there is no sense of panic. There are no raised voices. Now and then Cumming speeds his team along; 'Yes, chef' comes the instinctive reply.

Out of sight round the corner, dishes are being turned out with a steady fluency for the downstairs Cafe Rogano, which is thronged with couples and office parties.

There are, all told, five chefs de partie at Rogano: the Café chef, the pastry chef, the larder chef, the sauce chef, the vegetable chief, all of whom work alongside sous chefs. By close of play tonight, the café will have had 195 covers and the restaurant 180. They have lost count at the oyster bar, but the grand total for all three operations will be well in excess of 500. (Speaking of oysters ... 500 are sold here every day, 100,000 a year. Tourists love them.)

Many of the kitchen staff have worked here for years, though the current average is two or three years. Gordon has been at Rogano for a decade. Barry started out six years ago as a dishwasher and now runs the walk-in larder. Kit, the pastry chef, is a 20-year veteran ("our pastry chefs are an elite bunch", Cumming says.)

He introduces Mikaila, one of the patisserie team. "My newest girl," he says. "I've sort of adopted her. She's from Orkney and didn't know too many people down here. But she's done really well - she has just won bronze and silver medals at a big craft chefs' event in London."

Two other chefs, Ethan and Steven, are responsible for vegetables and garnish. Every dish, pot, pan and item of cutlery is washed by three industrious Nigerian night-porters - Gabriel, Obiagwu ('OB') and Michael. All three, it emerges, have degrees.

"One main scallop, one main venison!" Cumming calls out. "Could you get me a haggis main out, please?" He finds a few moments in which to tell The Herald that its doorway vantage-point is where, "a few years ago, we had a guy visit here to research a TV programme, which was set in a restaurant." The programme was Kitchen, with Eddie Izzard as a head chef.

Last orders upstairs are at 10.30pm, 11pm in the cafe. The kitchen staff are now deep, deep within their routine. Tomorrow, Sunday, will be busy as well, but it is also the day when the kitchen receives its intensive weekly clean.

It's all part of working in an institution such as Rogano. The festive season is profitable, but it does mean a lot of hard, concentrated, co-ordinated work.

As The Herald takes its leave, we hear the head chef call out once more. "Six Scottish oysters, starter scallops, one pheasant, one sirloin! Six Scottish oysters, fish soup, one main scallops, one main salmon." Upstairs at the distinctive front door, a party of four has just arrived. Their table isn't available, quite just yet. Give it time, I want to tell them. These guys in the kitchen downstairs have been on their feet all day.