Food and Drink: Look who's turning the tables: Restaurants come and restaurants go. Emily Green visits two that may stay - if the food improves

GUIDE BOOKS classify restaurants by cuisine, mood, amenities, district and price. Yet the most telling breakdown is never done, even though most of the restaurant-going public must be acutely aware of it. Restaurants fall into two basic categories: solid and ephemeral.

Solid restaurants run and run. The chef is a chef, not a bass player between gigs, nor a showman in monogrammed whites. The waitress is a waitress, not an aspiring film producer. There is a tangible spirit of dedication, which the French sum up with a card in the window stating, 'Le patron mange ici.'

No prizes for spotting the ephemeral. Shopfitters are at them with dismal regularity. They go from sushi to Cajun, to new wave Italian, to modern British, to Californian pizza, to French bistro in a series of quick changes. The more incarnations a place goes through, the more difficult for an incoming restaurateur to turn it around, to make it solid. Two new places are trying to do just that: Beth's in Hampstead, north London, and Palio in Westbourne Grove, west London.

The premises now occupied by Beth's have undergone some abrupt changes of late. Formerly it was the Hungry Hussar, and not long before that, Keats. Beth's, however, looks as if it means to stick around. It is as pretty as any in London: tall airy rooms, acoustics softened by drapes. A playful gingham motif runs through the place. The fittings have grace and wit and an understated, accessible sense of chic.

Service is so good it is as if Beth's has always been there. A silver-haired gent greets and appears to manage. Young waitresses are efficient and sunny. Bread is good and crusty. And prices respect the purse: Sunday lunch is pounds 8.50, a three-course dinner with wine starts at about pounds 25 per person.

If Beth's is to run and run, however, judging from a dinner for four last Saturday night, the food needs to improve. Of starters, an almond and fennel soup was porridge-like and bland. Devilled mushrooms, served on toast, were sour and school-dinnerish. Smoked haddock came with a dull lentil salad. The fish was a mound of chunks, as if it had been crudely hacked, then pickled (or ceviched). Its two cures, smoke and pickle, jarred with one another. One dish was good, however. Chicken liver pate was served with toasted brioche and a red onion compote, this last slightly heavy on cloves.

Of the main courses, a chicken breast was dry from overcooking, yet its skin was flaccid and caked with what tasted like packet chilli powder. A rough tomato salsa to the side gave little relief to the chilli burn. A bog-standard ratatouille came with a dry bulgar wheat salad. Lemon sole, spinach and a spoonful or two of lemon grass beurre blanc tasted of almost nothing. Only calf's liver, with a slightly glutinous but enjoyably garlicky mash, was sound.

Puddings were better, if uneven. Marmalade and Grand Marnier ice-cream was extremely rich, but fresh-tasting and good. A steamed chocolate pudding was dull and dry, served in cream that, at a guess, had been given a quick shot of vanilla essence. A lemon tart had excellent flavour and a sturdy crust, but it was skulking in syrup and its pudding was splitting, probably from having spent the night in a fridge. Banana fritters were cloyingly sweet.

How many of the meal's flaws were due to mere teething pains will become obvious with time. Right now it seems clear that Beth's ambitions and style are solid. I hope the food will follow suit.

Palio did not change its name in its last transformation seven weeks ago; it changed management. Formerly it was a stab by Whitbread, the brewer, at a modern Italian restaurant; before that it was a pub-cum-wine bar. The new proprietor is Antony Worrall Thompson, a magpie when it comes to food fads.

Typical of the bright and shiny ideas that he collects, then gives a playful spin, is a dish recently listed at his central London restaurant Zoe (formerly one of the Zen chain): confit of duck with macaroni cheese.

The food is just as weird and, to my mind, unpalatable at the new Palio. Something called 'charred steak tartare' was a contradiction in terms: basically a very rare hamburger with greasy chips and, for some reason, croutons with tapenade.

Another dish was sent back and served again, every bit as inedible as the first time: 'steamed mussels with greens, lentil and coriander broth' consisted of mussels so drastically undercooked that only a third of them opened; a salty broth, lentils swimming around; and leaves of frisee lettuce going lank on the surface of the bowl.

A white burgundy, Clos de Chenoves, cost pounds 15.25 and was delicious. The barman, a fleet fellow, is ace; the same goes for a charming manageress. Mr Worrall Thompson says a new chef is due in next week.

Beth's, 3a Downshire Hill, London NW3 (071-435 3544). Children welcome; special portions. Limited vegetarian options. Open 12.30-2.30pm, 7-11.30pm Mon-Sat; 12.30- 3.30pm, 7-11pm Sun. Switch and major credit cards except Diner's.

Palio, 175 Westbourne Grove, London W11 (071-221 6624). Vegetarian meals. Children welcome; special portions. Loud music. Open 12 noon- 11.30pm Mon-Sat; 11am-11pm Sun. Switch and major credit cards.

(Photograph omitted)