Petersham Nurseries Café, Church Lane, Off Petersham Road, Richmond, Surrey

It may be that the sun has gone to my head – I've spent a golden couple of hours in a dappled, greenery-filled glasshouse, drinking Prosecco and rose syrup – but surely Petersham Nurseries Café is the prettiest restaurant in Britain? It certainly looks gorgeous on a sunny spring day – a rus in urbe, or at least sub-urbe, idyll, which still has the power to take the breath away. The Café was born eight years ago, when owners Gael and Francesco Boglione saved a ramshackle nursery at the foot of Richmond Hill from developers. Initially it was just a single table in the main greenhouse, serving 10 guests. But word spread, and soon Petersham was a phenomenon, regularly mentioned alongside the country's finest dining experiences.

The nursery itself, with its lovingly curated plants and exquisite homewares, may bear as much resemblance to the average garden centre as your back garden does to Sissinghurst, but despite its enormous success, the Café is still at heart a casual place. More Northern California in feel than south London, with its vine-wrapped pillars, bricolage furnishings, and bare dirt floor, it seems delightfully organic, rather than a Daylesford-style exercise in twee escapism.

Recently, though, the greenhouse has turned into a hothouse for Skye Gyngell, the cook who put Petersham on the map. Stepping down from her role as head chef, she described last year's unexpected award of a Michelin star as a "curse", which had pulled in a new breed of demanding customers who found fault with the Café's casual style and simple cooking.

Skye is a tough act to follow, but the Bogliones have recruited another inspirational Australian, Greg Malouf, a battle-hardened pro who comes from Melbourne with a stellar reputation forged at his restaurant MoMo, and showcased in a clutch of handsome cookbooks. Malouf, a regular visitor to Britain, has a long-standing relationship with Petersham, having guested and held book launches there. Of Lebanese heritage himself, and passionate about Middle Eastern cooking, he arrives in this country with a determination to give a kick up the backside to our "depressing" version of the cuisine he loves. He's chosen a slightly odd place to do it from – Petersham not only isn't at the centre of London's fast-moving food scene, it isn't even in the centre of Richmond.

Malouf had been at the helm for a couple of weeks when I went for lunch, and was trialling his first dishes on the menu, marked with his own logo of a befezed man. Piles of his beautiful books were on sale by the till. If he were one of the plants on display next door, one suspects he'd be with the sunflowers rather than the shrinking violets.

Ordering only the Malouf dishes proved to be something of a challenge; everything on the daily-changing menu cries out to be sampled. But a starter of spiced rabbit was superb; the meat presented as leg and rolled loin, and partnered with a smooth parsnip skordalia, juicy hunks of chorizo and the bitter bite of puntarella. Mixed leaf salad, dressed with viola flowers from the nursery, was as bonny a plateful as you could wish for, each leaf coated with a zesty, Parmesan-rich dressing.

There's something wonderful about eating fresh, green, unmessed-about-with food in an al fresco setting. And a tagine of cumin-fragrant aubergine, potato and chickpeas, felt a bit heavy to work as a lunch dish on an unseasonably sunny day. But grilled poussin, its skin rubbed with spices and cooked to a crisp char, was fabulous. Accessorised with winter tomatoes, a caramelised mulch of shallots and griddled flatbread, it was a perfectly balanced plateful.

My guest Nell is a friend (and former sister-in-law; it's complicated) of Malouf's, and we fully expected to be rumbled. But we lunched apparently undetected, challengingly seated next to a party of bankers holding a retirement lunch. In most restaurants, having your starters accompanied by a booming speech hymning Tim's achievements would spoil the atmosphere, but the airiness and rampant greenery here meant that we remained benignly undisturbed.

The synaesthetic feast of sensory pleasure – the scent of honeysuckle, the warmth of the sun filtered through rush blinds, the rainbow of blues on the shirts of our neighbouring bankers – went into overload with our puddings. Blood-orange granita melted in the mouth, leaving a delicate aftertaste of orange blossom. Even more sensational was an ice-cream freighted with pine nut-infused praline.

Malouf emerged to share a fresh mint tea with us, seeming rather dazed to find himself cooking seasonal food on the wrong side of the world, where the seasons are completely reversed. But he is clearly relishing the challenge; there was nothing wobbly about our lunch, which felt true to the quirky spirit of Petersham, but grounded in rock-solid professionalism. After eight inspiring years, Skye may have moved on, but she can rest assured that whatever the Michelin men decide to do about that pesky star, her legacy is in very safe hands.

Petersham Nurseries Café, Church Lane, Off Petersham Road, Richmond, Surrey (020-8940 5230)

About £40 a head before wine and service

Food ****
Ambience *****
Service ****

Tipping policy: "Service charge is 12.5 per cent discretionary, of which 100 per cent goes to the staff; all tips go to the staff"

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The Treehouse

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