I don’t normally do this – go back for a reheat, a second bite of the menu. Many restaurant critics do: I know they like to be thorough, and they’re usually fat. All the colonically obsessive Miss Marple American ones go dozens of times in different costumes, trying to pretend that their review will be definitive. But a restaurant isn’t like a film, or even a play, for which a critique of one performance will be applicable to all performances. It’s more like a football match: it happens in the same place, with the same team, but the results are always different. The most difficult trick in football, sex and catering is consistency. What I review is one meal on one day, and then people write to me and say: “I always thought you were a pompous charlatan, but now I know you’re also an emery-tongued, epicureanally clod-gobbed shyster. Myself and the lady wife, hosting old and dear friends, who both happen to be much-feared JPs, had the misfortune to repast in an establishment you fulsomely recommended. Imagine our constellation when we were offered dung and vomit, served by zombies, and charged Russell Grant’s waist measurement in pounds sterling for the pleasuring. Consequently and consecutively, we have taken a solemn vow never to read any of your putrid, mendacious drivel ever again, and I, for one, will never touch another newspaper for as long as I live, unless it is to clear up after Gay Boy, our cocker. Yours etcetera.” You’d be surprised how many of those I get.

I try not to return to recently reviewed dining rooms because, if it’s bad, why would you? And if it’s good, well, it’s embarrassing. But last week, I was asked out to dinner by friends, none of whom was a JP, and when I got to the address, I realised it was Haiku, a place I wrote about a couple of weeks back. The Blonde and I had gone for lunch, where we had been the only customers, and although I didn’t approve of the jabberwocky menu, what we were served was well made. At dinner, the restaurant was packed, claustrophobic and Stygian. The food wasn’t 20% as good as our lunch. It arrived in fits and starts. The staff, stumbling in the blackness, rarely knew which table they were serving. It was an exhausting, unsatisfying and frustrating evening. As we left, my friends sniggered: “But you gave it such a good review.”

What could I say? Well, I can say this. Haiku got four stars for lunch, and for dinner it gets one. The kitchen can’t cope with the demands of a full dining room. I’m perfectly aware that the fact that it was full may have had something to do with my review. Of all the culture’s glittering amusements, restaurants are the only ones that can actually be made worse by a positive critique. And let that be a lesson to others. You may think it’s all over when I leave, but, like a fey Freddy Krueger, I may return.

One of the greatest aids to improving restaurants in this country has been the evaporation of the class system. Class now exists only in polemics and among a few angry nostalgics who yearn for the comfort of old conflicts. Restaurants were invented as a product of republican democracy, and the fact that anyone with money and the desire can book any table in the country without embarrassment is a good thing. Few restaurants insist on ties or jackets – that sort of old-fashioned snobbery is as winning and attractive as cockroaches in the bar. Though the class has been taken out of dining, that’s not true of menus. Dishes retain their ancestral accent and the nature of their heritage. Soufflés are always risibly lower middle class; clear soup is starchily aristocratic; and fried fish and potatoes are nobly of the people. Fish and chips is a dish that resists any attempt at upward mobility: it’s impossible to refine or titivate it. The closer its preparation to lino and tiles, the better it is. You can’t eat fish and chips with your tongue in your cheek.

So, Geales starts off with a credibility problem. This is an old fish-and-chip restaurant on the edge of Notting Hill, left over from a time when this was a run-down area of immigrants and indigents. Now it finds itself in an enclave of quiet streets of £2m back-to-back artisan cottages, so it worries about its wine list and whether it should offer balsamic as well as malt. But it was here first, before the rich and fabulous, and it’s a bit of an institution. And, as with most culinary institutions, over the years, the food had got worse and worse, until it seemed to be there just to spite the neighbours with the awful smell of overfried oil.

Recently, it’s had a makeover, and I went with a party of 12, which is a strain for a kitchen, but then, a chippy is a place you go mob-handed. The little terraced dining room has been done out simply. I noticed a couple of paintings by Reg Gadney, a favourite among restaurant critics. We were punted upstairs to a room obviously kept for the ugly, the demented and families with multiple ADD children. The restaurant struggles to juggle its salty origins with the aspirations of its clientele, so the plainly spoken battered cod, hake, haddock and sole is accompanied by wild rocket and parmesan salad, prawn cocktail and soft-shell crab, while the chips compete with buttered new potatoes.

This must be the third or fourth restaurant I’ve reviewed in the past year that’s trying to drag English fish and chips into the meritocracy. Mostly they do it quite well. Here, the prawn cocktail was a misbegotten thing, shorn of its Marie-Rose dressing and shoved into a characterful glass jar that had all the ergonomic comfort of liquorice socks. After that, I went for the haddock and chips, which are not fried in beef tallow, so from the off they’re not going to be great. But they were good. The fish was rather midgety by northern standards, but decent for Notting Hill, although, consequently, the ratio of flesh to batter had changed, and it was a bit like a fish pasty. The chips, though, were really good: thick, floury, piping and crisp. The mushy peas were Eliza Doolittle: a common bird talking posh. There was a badly made jam roly-poly for pudding. Not enough suet. Probably not any suet. You can’t lighten up this sort of food and keep its character. It was invented out of the cheapest ingredients for people who were ravenous, did hard work, lived in cold houses and coughed themselves to death before they were 60. It was made to be filling, not subtle. If you don’t like that, then eat something else.

Geales, though, is better than it was. The atmosphere was warm and congenial, the service slow but willing. Fish and chips is never going to be anything more than fish and chips, but that should be enough – it’s earned the right just to be itself. But when all is said and done, battering is not the kindest thing you can do to any fish, and it wasn’t done for gastronomic reasons, but to add stomach-filling volume and calories. The vinegar is malt, and £10 for a fish dinner may make you suck your teeth and shake your head up in the mill towns of Lancashire, but, let me tell you, it won’t cover the baby-sitter’s taxi ride home down here.

Geales

2 Farmer Street, W8; 020 7727 7528; Mon-Sat, noon-11pm; Sun, 6pm-10.30pm

5 stars: Whizzer and Chips; 4 stars: Chippendale; 3 stars: Chip off the old block; 2 stars: Chip butty; 1 star: Chip on their shoulder

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