Time to tighten those belts...

You can spot those people who had a really good time at New Year. They're the ones cowering behind the sofa when the postman comes. Envelopes thud through the letterbox and, as each bill strikes home, it sucks the life from even the most generous overdraft.

Faced with such an assault, the obvious strategy is to cheer oneself up. Some gratuitous spending is called for. Lunch at Assaggi would do the trick, or dinner at Nahm or Hakkasan... But this is when you hear a faint but persistent inner voice - your conscience - and, unfortunately for you, it doesn't know that it should be seen and not heard.

This is the dilemma: so many of the places that would be perfect for dispersing the mid-winter blues are wickedly expensive, fully booked, or both. Now is the time to look out some of the 'first reserves', places that offer good cooking but are not so expensive that they require a second mortgage, or so popular that they are fully booked until Easter.

Whatever the weather in London, it's always sunny at Assaggi . Stunning, and stunningly simple, Italian food is teamed with slick service. From the carta di musica (Sardinian bread), the meal proceeds through perfect pasta to fish or a veal chop and then ricotta with cooked honey. The drawbacks? It is invariably fully booked, and pricey. Normally, we'd just go for it but now it makes sense to visit the first reserve.

Al San Vincenzo is also small, and resolutely Italian. A family-run place, its dishes are simply presented and very good - potato and lentil soup is made to measure for this time of year, and 'fresh eels pan-fried with chilli, onions and lemon' is a masterful combination, the richness of the eel cut by the citrus and chilli. It is a deal easier to get a table at Al San Vincenzo than Assaggi, and it is also more wallet-friendly, which may help keep your conscience quiet. Dinner for two, with wine, costs about £80.

David Thompson's restaurant, Nahm , sticks to the principle of showcasing distinct flavours, but is notoriously pricey. If you fancy some intense Thai flavours and delicate presentation, but can't stretch to Nahm, perhaps you should consider riverside newcomer Lan Na Thai in Battersea. The richness of the carved wood interior will charm, as will the elegant cookery which revolves around strongly flavoured dishes: talay tong (fresh seafood) is delicious and the richness of the ma kaur yow pad toa jeaw (aubergine cooked with garlic and fresh chilli) also appeals.

What's more, you will be able to get a table here, and the bill - at about £40 for two, with wine - will not be as fearsome as at Nahm.

It is a shame when a restaurant slips from the food pages into the gossip columns. For the proprietors it represents valuable publicity but for customers it tends to mean soaring prices and unbookable tables. The food at Nobu is terrific, head chef Mark Edwards knows his stuff, and the quirky Japanese/Peruvian dishes are delicious. But Nobu has joined the ranks of unbookables, so it is time to go to Clapham.

There you'll find Tsunami , which has powered from a low-key opening to an enviable reputation in the space of a few weeks. Its master sushi chef Singi Nakamura has served time at Nobu and Ubon. The food at Tsunami is impressive. Look out for Sunkiss salmon, and the duck breast with Nashi pear. As word gets out, Tsunami is getting busier - but it is still a doddle to get into compared with Nobu. And think of the money you'll save - dinner for two, including wine, costs about £50.

Le Gavroche is the sort of French restaurant to which you take your bank manager when you're in begging mode. There is a particular kind of formality that is comforting to people who must wear ties every day. Michel Roux's food is precise and good: all the classics are represented and, miraculously, some have even been improved. Service is silky smooth.