Al di Là Trattoria, 248 5th Avenue, Brooklyn, New York (001 718 783 4565). Meal for two: $150

Frej, 90 Wythe Avenue, Williamsburg, New York (001 347 286 6241). Five-course tasting menu: $45

A hot summer's evening in New York, and I am joining the bridge-and-tunnel crowd. For decades it was a term with its own in-built sneer. If you were bridge-and-tunnel you lived outside Manhattan and only came on to the island at weekends to clog up the obvious off-boil restaurants. Real Manhattanites went out to play in the newest places from Monday to Thursday; at weekends they hunkered down and waited for the badly dressed tourists to shove off. Now it's reversed. For if you want to eat well in New York at a reasonable price and you live in Manhattan, it's your turn to become bridge-and-tunnel. You go to Brooklyn. The lower rents, more flexible spaces and, most importantly, the presence of a younger crowd that can't afford to live in Manhattan have made it restaurant mecca.

One evening I head over to Williamsburg, which has long been cool and has now gone Arctic, to have dinner at Frej, pronounced Fray. Williamsburg; pop-up; Swedish. It's cool cubed. It's also very good. There is squid with the crunch of kohlrabi, the sour of cucumber and a smear of a squid purée. There is scallop with seaweed and beef cooked in hay with wild spinach and a fine broth, all served in an industrial space of polished concrete. A five-course tasting menu costs $45 – extraordinary value for the intricacy of the food. Needless to say it's booked out weeks in advance and I had to pull every string to get a table. Us bridge-and-tunnellers know no shame.

Comfort yourself, instead, with a trip to Al di Là – it means "beyond" – in Park Slope, on Brooklyn's west side, a neighbourhood of old low-rise houses built of brick the colour of clotted blood, with stoops and fire hydrants of the sort Norman Rockwell would have painted. The restaurant, which was one of the earliest to set up here and styles itself as a Venetian trattoria, is pure Brooklyn: the distressed brickwork, the artfully peeling paint of the beaten-out ceiling, the drapes and the huge glass chandelier built for a space 10 times the size. It's a very knowing kind of dilapidation.

The cooking, like the room, is built for comfort rather than looks. I wouldn't call it ugly, but you wouldn't frame pictures of it. A stew of oxtail and cuttlefish in its ink is a big black mess placed on a pillow of soft polenta. What matters is the hit of flavour: the ripeness of the seafood, the depth of the beef, the unforced, slightly bitter edge to the ink.

Another starter of a perfect risotto layered with sliced scallops cooking in the heat of the rice, under strands of mushrooms, the whole under a massive snowfall of salty hard cheese, is a companion piece. We share a dish of large pasta tubes – rigatoni's older brother – under a dense ragu of slow-cooked pork shoulder with a smear of melting goat's cheese for acidity, and hug ourselves for having had the smarts to drive over the bridge.

Mains don't quite maintain the standard. Both grilled calves' liver with sweet-sour onions and a pork saltimbocca, the escallops breaded with sage and prosciutto and fried, are a little heavy going. But we press on to dessert. There are sorbets of sour cherry, apricot with vanilla and kiwi and, better still, deep-fried and sugared doughnuts made with ricotta cheese, and a chocolate sauce to dip them in. If the sound of those doughnuts doesn't do it for you, I'm not your guy.

It would be easy to describe Al di Là as a neighbourhood restaurant and in the sense that it's located in a neighbourhood where people live, I suppose it is. But that, like so much else going on in Brooklyn, doesn't do it justice. It is the dividend of ludicrous inner-city rents and rates. In London, we are seeing a little of this. I hope we see more. As to why I'm reviewing in New York, I often get emails asking for restaurant recommendations across Britain. But I get asked most often for suggestions in New York. Clearly more of you go there for dinner than, say, Bristol, where I was last week. And so my advice: endure the arterial clog across the bridges to Brooklyn. It's a small price to pay for eating well.

• Email jay.rayner@observer.co.uk