The first meal of the day may be the most important, but at Smithfield market it's more serious than that

The Cock Tavern, The Poultry Market, Smithfield, Central Markets, London EC1. Tel: 020 7248 2918 Open Monday to Friday, 6am to 2.30pm

The Cock Tavern, The Poultry Market, Smithfield, Central Markets, London EC1. Tel: 020 7248 2918 Open Monday to Friday, 6am to 2.30pm

It's not the most romantic market in the world, Smithfield. It doesn't have the beautifully manicured old women of Barcelona's La Boqueria, or the fatty exuberance of La Halle de Lyon. Nor does it have the rows of torpedo-like tuna at Tokyo's Tsukuji market, the surreal turtle butchery of Singapore's wet market, or the pet rhesus monkey who sits on a sofa watching television and eating beef satay at Bangkok's Au Tor Kor spice market.

It's really just a nice old big shed, threaded by a brightly lit central oesophagus lined with carcasses. Some of these hang out the back, and some walk around out the front wearing white coats. By 6am, there is a line of vans ringing the entire market, motors humming like lowing cattle, headlights warm against the rump of the one in front. Did you know, by the way, that it's dark at 6am? I'm not sure I did. It's a new, different kind of dark, a colder kind that nips at your heels like a cattle dog.

Luckily the Cock Tavern, downstairs under the poultry section, opens at 6am to feed the various sub-species around the area who have been up all night. They come in shifts, or at least at the end of their shifts, from the meat market in overalls and hard hats, from Bart's hospital in buttoned-up overcoats, and from the local nick in thick serge jackets with the collars turned up. At one stage, I have The Bill to my left, Casualty to my right, and an episode of EastEnders directly ahead. The girls behind the bar know most of the workers by name, living proof that this is no Ye Olde English Pubbe, but an honest working local boozer.

I don't really need to paint a picture of the place - you know it already: the long wooden bar, the snug corner of 1970s splendour, the two open dining-rooms of vinyl chairs and checked table cloths, the Beatles music, the old market signs and framed photos of bomb damage during the Blitz. And in the kitchen, the steadfast breakfast cook who has been dishing up eggs, bacon, sausages and beans for 35 years.

You know the menu, too. Tea is 40p, coffee is 55p, toast is 25p and set breakfasts run from the Cowboy Breakfast of double bacon and beans at £1.90 to the full-on Cock breakfast at £6.25. I order the Smithfield breakfast for £5.10, a real plate-coverer. The bacon (from Smith's stall upstairs) is a treat, thick-cut and salty, and the egg is cleanly set, with a just-runny yolk. Kidneys are cooked with surprising delicacy, and black pudding is suitably lush and fruity. A banger is blah - bready and anonymous tasting - the baked beans are baked beans, and the thin buttered toast is something that nobody has thought very much about.

My wife, who thinks an English Breakfast is something that comes in a cup and saucer, strikes gold with an egg and bacon sarnie (£1.50). The same great bacon, without a drop of grease, lies sandwiched between freshly buttered soft, white, thick crusty bread along with a gently cooked egg that oozes apologetically, without dripping beyond its borders. This is food that is so plain and simple, it is almost sophisticated. It's about half an hour too early for me to go for a pint of Young's Bitter, so tea it is, a big pot that bulges with about three too many tea-bags.

It's all so wonderfully ordinary; the perfect panacea to a soul troubled by Cuban foie gras on beancurd crisps frizzled with tamarillo and sea urchin jus served by people with expensive hair.

But for how long? The Smithfield/Clerkenwell area is being reinvented on an almost daily basis, as the City boys and girls move their DVDs and gym equipment into urban lofts and bond over raw tuna at Yo!Sushi and foie gras at Club Gascon. They don't so much live as lifestyle here, contributing to the economy but not the community. They'd rather do breakfast ironically at John Torode's smart new Smiths of Smithfield across the road, and watch their property values rise with every new corner Prêt à Manger. I go back to The Cock for lunch, but lacklustre roast pork and a dry roast beef sandwich convince me it's a breakfast place. There are other fry-ups in Smithfield, and probably even better ones, but the Cock hits the spot, because it's filled with people who have been working all night rather than playing. I wish it were better, but I suppose it's enough that it's there at all.