Bristol Lido, Oakfield Place, Bristol (0117 933 9530). Meal for two, including wine and service, £80

There is only one thing better than working up an appetite via a brisk bout of exercise before lunch: working up an appetite by watching someone else's brisk bout of exercise before lunch.

The restaurant of Bristol's Lido is perfectly positioned for a little vicarious fitness. It sits on the first floor of the newly renovated, glass-walled and sun-drenched building, with its summery yellow walls and hunky, solid beams. On a glowering and chilly winter's day, with the steam rising off the azure-tiled pool, it must feel like having a ringside seat at a cloud factory. But on our visit the spring sun shone and the water dappled, and sturdy young Bristolian mothers ploughed their watery furrows in such an exhausting manner that I had no choice but to pull lumps off the impeccable smoky-crusted bread placed before me just to help the swimmers build up their energy.

Sometimes when I sit down at a table I know that a restaurant is right – from the mood of the diners, from the cheeriness of the waiters, from the writing of the menu. Especially the menu, and the one at Bristol's Lido is a corker. Partly it is down to the words "wood roast", which – like "cotton-sheeted" and "sun-kissed" – come sodden with promise. It is hard to imagine the ingredient which would not benefit from wood roasting.

Here, on a menu which takes much of its inspiration from southern Europe, and many of its ingredients from its own kitchen garden, wood roasting is reserved for quail and venison, fish and potatoes, and that marvellous bread. Flavours are big and the essentials carefully managed. They make very fine pasta, for example, of the soft, silky, egg-yellow type, used here in ravioli of venison. The meat is long-braised to a tangle of glossy fibres, the pockets dressed with soft cubes of roasted pumpkin and an artery-hounding sage butter. Discs of more pumpkin turn up deep fried, drizzled with a slick of honey and with crumbly lumps of a mild goat's cheese, the whole sprinkled with oregano. It is a very simple, very effective plateful.

Main courses were equally pleasing, if a little clumsier. There was no arguing with the wood-roasted fillet of grey mullet, the skin glossy and crisp and the flesh still falling apart on the fork. The accompanying salad of fennel, blood oranges and potato could have benefited from a little finer knife work and something salty – anchovies? capers? – to perk it up. Likewise, you could not fault the flavours in a dish of slow-roast shoulder of lamb, the hunks of muscle then seared off and placed on a tomato-flavoured stew of bulgur wheat and cabbage, and dressed with a little yogurt. It was a big, paunchy, self-assured dish, and if they'd siphoned off some of the fat it would have been perfect.

Starters are around £7, mains £16-ish, though they do offer two small versions of most for £10. The dessert list is headed by a selection of ices to make you dream of real summer days: blood-orange granita; rhubarb and Campari sorbet; rosewater or chocolate, and white chocolate or tonka bean ice cream. We tried a scoop of their take on rum and raisin, made with Pedro Ximénez sherry. It was stuffed with soft fruit, and boozy and rich. A scoop of salted butter caramel had that perfect balance of sweet, salt and lightly burnt. As did their night-dark chocolate and salted caramel tart, with the sort of crust that makes a crack when you break it. Much lighter was a rhubarb and rosewater mess, a photograph of which could sit happily in a food dictionary as the definition of "girl's pudding".

What's striking is the effort that has gone into creating a very good restaurant, in a place that didn't necessarily demand it. The Bristol Lido is about its pool, its spa and the waterside café. The quality of the food here, in the tangled back streets of Clifton, is unexpected. And all the better for that.