Nicholas Lander reports from increasingly fashionable Notting Hill Gate on London's most elegant new fish shop

For the past 13 years, a long time in the restaurant trade, Clarke's and Kensington Place have lived in a most unusual, friendly and symbiotic relationship no more than 200 metres from one another along Kensington Church Street in increasingly fashionable Notting Hill Gate.

Whilst Clarke's has oozed discreet charm and quiet, Kensington Place, or KP as it is affectionately known, is an altogether more raucous environment with perhaps the noisiest acoustics in town as the voices of the 2000 customers it serves a week rebound around its minimalist interior.

As chef/proprietor Sally Clarke has struck firmly to her culinary principles, combining the best of British produce with techniques first learnt in California to offer a small but well balanced menu at lunch and a no-choice menu in the evenings, KP's range has broadened with the growing perspective and experience of its chef, Rowley Leigh, probably London's most genial personification of this particular profession.

They even complement each other at breakfast. In its small cafe next door Clarke's serves some of the best bread, croissants and pains au chocolat in town, all of which are made in its own bakery nearby as are their incomparable chocolate truffles, whilst KP now opens from 7.30am for anyone able to face a full, cooked English breakfast at this early hour.

There is now, however, a new and somewhat surprising ingredient in this heady culinary mix. KP has recently been extended to provide a type of shop that has regrettably been disappearing all too quickly from high streets up and down the country over the past 20 years, a wet fish shop. This is not just any fish shop – it is perhaps the most elegant, and certainly for its size the most costly, fish shop ever built.

Leigh waxes lyrical about the shop's raison d'être. 'I have always wanted KP to be as close to a Parisian brasserie as possible, so when I plan my main courses for example I always ensure that they are fully garnished with at least one vegetable accompaniment and either potatoes, rice or pasta. And all those great French brassseries have their corner sites piled high with crustacea. I have always dreamt of doing something similar here.'

He looks far less enthusiastic when he describes the planning process and the shop's initial trading. 'This was just an empty corner with a letter box on it. We got permission to move the box but then realised that to store and display the fish properly in such a restricted space we would need stainless steel shelving that, rather like a sea serpent in outline, followed the bend of the external wall. A Scottish firm did a beautiful job but by the time we opened the total cost was around £200,000'. Such an investment would have sunk any individual restaurant but 18 months ago KP and its sister restaurants, Launceston Place and The Brackenbury, merged with The Avenue and Circus, providing a stronger financial base for this risky expansion.

This little retail gem can squeeze in no more than six customers at a pinch to check out the three sections of shelving which contain respectively fresh fish, whole and in fillets, crustacea and smoked fish and finally, cooked dishes, fish soup, fish cakes and fish pies, from the restaurant's kitchen. As I stood in the queue behind a customer who, having parked on the double yellow lines outside, proceeded to pay for two kippers with a £50 note I realised that profitability and Leigh's piscatorial dream may prove difficult to reconcile.

'At first,' Leigh admitted, 'the shop was losing as much as £2000 a week but we have got that down to under £200 now. We are buying about a ton of fish a week for here and the other four restaurants in the group and that is bringing economies of scale for the restaurant and the shop's customers. And in the process I have learnt just how good Billingsgate, London's long established fish market can be. Like a lot of chefs I used to think that it was vital to deal directly with fishermen at the coast but now I combine that with buying on the market and it certainly broadens the choice.' Leigh even confessed that one customer's request for white grouper for a private dinner party led him to appreciate a fish he had never even been offered before during 25 years at the stoves.

Judging by the quality of KP's fish cakes which I have cooked at home and the fish dishes I have enjoyed recently in the restaurant – herring roes on toast, fried squid with chilli jam and crème fraîche, roast skate with pancetta and grilled sole fillets with purple sprouting broccoli – Leigh is as impressive a fishmonger as he is a Head Chef.

Clarke's, 124 Kensington Church Street, London W8, 020-7221 9225
Restaurant closed at the weekend. Lunch from £22 two courses; set four-course dinner £44

Kensington Place, 201 Kensington Church Street, London W8, 020-7727 3184
Open 7 days. Lunch from £16.50 for three courses, a la carte £30.

The Fish Shop at Kensington Place 020-7243 6626
Open Tuesday-Saturday, deliveries to west London.