What do two suited young men, a fabulous pensioner in a multi-coloured spotty dress coat and London’s wine crowd all have in common? They all dine at Medlar.

This exquisite little restaurant was opened by two friends in 2011 on a non-descript part of the King’s Road – the section that houses an array of charity and bike repair shops and is set between the fashionable Bluebird restaurant and the dusty World’s End. On opening, national restaurant critics fell over themselves to praise its dining room: now, with owners Joe Mercer Nairne and David O’Connor still in the kitchen and on the floor respectively, and Medlar’s award-winning sommelier Clément Robert still delivering his quiet wine expertise, things are as excellent as ever.

We were sad not to be able to sit outside for lunch on a sunny afternoon – there was space a-plenty but then everything would have come with a side order of exhaust fumes. Inside is wholly different – a quiet zone with light grey canvas walls, a minimalist flower mural stretching across the entrance, bright green light fixtures and canvasses plastered with bright paint splashes. The best seats –booked often – are two bright green booths set in a light-filled plot at the back. Meanwhile tables are white clothed, and squidgy dining chairs elegantly fitted in mottled grey leather. So far so elegant.

Duck egg tart with red wine sauce, turnip purée, lardons and sautéed duck heart

At 1pm there are six tables of people, some of whom look like regulars. On ours there is butter – plain, not voguishly whipped or smoked – and bites of yielding herby focaccia. But it is two signature dishes that lift us to unexpected heights of joy and comfort. Crab raviolo is a glut of textures and reminders of the sea – strands of salty, crunchy samphire, leeks, and endless brown shrimps dancing through a rich bisque sauce. When it arrives the next dish looks like something from a breakfast menu but it delivers so much more: a chemistry of crisp, salt, earth and rich meatiness. We suck on small pieces of gently sautéed duck hearts, these sitting in thick red wine sauce and neighboured by blobs of turnip purée and lardons. The tart, topped with a single fried duck egg, has pastry so skilfully made that we decide it is surely the lightest and crispest in the area.

Cornish hake is a happy marriage of delicate fish with borlotti and runner beans, morceau sausage and pistou, while beautifully cooked pieces of Anjou pigeon are quenched with a bright mint and coriander pesto, king oyster mushroom, chargrilled broccoli and endive – worth the £4 supplement.

We choose well, too, with puddings – is it possible not to at Medlar? – which are a silky lemon curd ice cream with blueberry compôte and langue de chat, and super English strawberries with a sparkling array of side pieces – Prosecco jelly, mint and lime granita, strawberry sorbet, and the occasional light crumble of meringue. Petits fours are further reminder of the keen pastry work at play – gleeful passion fruit marshmallows and melt-in-the-mouth chocolate truffles.

If I lived nearby I would eat here once a week. I suspect some locals actually do.

What we drank: 2010 Le Soula, Vin de Pays des Côtes Catalanes

Medlar, 438 King’s Rd, Chelsea, SW10 0LJ

Medlar is just one of the extraordinary restaurants who will be taking over our Sussex Cellar for one night only, creating an exclusive feast for just 40 people as part of our Cellar Series.