The Lock, Tottenham, London

If one of the keys to restaurant success is location, then chef Adebola Adeshina and restaurant manager Fabrizio Russo have taken quite a risk. The business partners have opened their first restaurant, the Lock, next to Tottenham Lock.

This is not quite in the same picture-postcard category as, say, Teddington Lock. Yes, it is a regeneration area. But no, it has not yet been regenerated.

Still another key to restaurant success is imagination. On this, the business partners have certainly scored. The Lee Valley, where the Lock sits, is an area of London that will soon be transformed - British event planning ability permitting - by preparations for the 2012 Olympics. All the pair must do is to survive the first few years, then soak up the area's new-found status.

A lenient lease from landlord Lee Valley Estates is helping (for the sake of regeneration, it's in everyone's interest that restaurants such as the Lock work), but Adeshina knows he has to get the menus priced right.

"I'm trying to be a creative and successful chef, but I also need to be a businessman," he says. His strategy is to focus on food costs, making sure every dish balances expensive ingredients with less pricey items.

So sea bass gets combined with a pasta al forno (£15.95), a kind of pasta cake made with cooked pasta and Cheddar cheese; halibut comes with braised cabbage and mushy peas (£12.95); and rump of lamb with bubble and squeak (£13.95) is made with bacon lardons to give the vegetables an extra kick. Food costs are currently kept at 26% of the menu price.

Adeshina is comfortable working with cheaper ingredients, which give the cosy, homely feel to the menu that he wants to achieve. This also tests him in the kitchen. "What differentiates you as a cook is how you do something tasty starting with just a bowl of rice," he says.

A pasta and risotto course, with a different risotto each day, gives diners a lighter option and keeps costs down. This Italian slant aside, the rest of the menu is more modern European, with dishes such as a starter of pan-fried scallops served with plantain.

While not actively trying to create a multicultural menu, details such as the plantain allow Adeshina to reflect a little diversity. "In France, you get foie gras," he says, "so here, with me, you get my experiences. We can't afford lobster and Champagne anyway, and it wouldn't make sense with our market."

That market is fairly well mixed between local businessman coming in at lunch (about 20 covers, served slightly smaller portions) and groups of friends and couples eating in the evenings (about 30 covers). Sunday lunch, however, is a growing market, with about 50 covers being served. Adeshina charges a very reasonable £10 for two courses, with diners starting with soup or salad, or paying a supplement for an à la carte starter.

"We are a restaurant, not a pub, but I am not ashamed to cook Sunday lunch," he says. "There are 10 pubs around here charging £8 for Sunday lunch with microwaved potatoes, so I know we can cash in on the market."

Adeshina has already found that by working with local traders down the road in Walthamstow Market he can get much better prices for his meat. He can get aged Scottish beef foreribs for a fraction of the price he was offered in the city's West End, and he has not yet once paid for stock bones.

"We have developed a good relationship with the market," he says. "It works for us because our local customers like to know we are buying meat from there, and the butchers come here to eat."

Building up that local following is crucial and, with Adeshina and Russo both having worked in the West End (they met when they were working at the Portman hotel, where the former was head chef; he has also done stints at Bonds, the Capitol and the Square), they want to start persuading local diners to save themselves the cost of the central London traffic congestion charge and eat out close to home instead.

They also plan to change the furniture, which they inherited, and increase the brigade in the kitchen to about four, but for the moment they are building one step at a time. "We have to be very careful," says Adeshina. "We are trying to build a long-term business."

• Goats' cheese salad and truffle, £4.50
• Smoked salmon tartare, £6
• Ham hock terrine with taleggio cheese bruschetta, £5.50
• Roast monkfish, potato gnocchi and mushrooms, £17.95
• Caramelised pork belly and cream leek mash, £12.95
• Chargrilled aged Scotch forerib steak (minimum order, two people), £24.50
• Chocolate tarte, £5
• Prune and Armagnac mousse, £5
• Crème brûlée three ways, ginger, vanilla and lemon grass, to share, £7.50

The Lock Dining Bar, Heron House, Hale Wharf, Ferry Lane, Tottenham N17 9NF [map]. Tel: 020 8885 2829