Clarissa Dickson Wright, 45, daughter of the Queen Mother’s renowned surgeon, Arthur Dickson Wright, was the youngest ever barrister called to the bar. She practised for 13 years, decided she wouldn’t have any difficulty becoming a judge, and threw down her briefs to go to the West Indies and cook on a charter yacht in 1977. Permanently, she thought. But soon, feeling like some time in London, she took over a luncheon club in St James’s. Then, fancying a spell out of London, she applied to run a pheasant farm in Sussex. On being asked whether she knew all about pheasants (she knew nothing), Clarissa replied haughtily: ‘One does, doesn’t one?’ And got the job.

She followed this with a period of doing private catering. Then, deciding to go back into the law, naturally she fell into managing London’s specialist bookshop, Books For Cooks, just off the Portobello Road. Tonight Clarissa is our hostess. She was brought up to have dinner parties. Her mother had six ‘indoor’ servants. ‘I never thought anything of sitting down for dinner with 16,’ says Clarissa, sipping a glass of mineral water.

We’re sitting in the garden of Clarissa’s friend, Lady Mary Stewart, in the shadow of Harrods. ‘Versailles’ is what the serene Lady Mary laughingly calls her garden, because it is all green and white.

We’re here because this is Clarissa’s second home. Clarissa garden-sits for Lady Mary whenever she is away on yoga tours, preferring Lady Mary’s garden to her own lack of one in Battersea. But tonight Lady Mary, author of Yoga for Children, is in town.

Typically, some of Clarissa’s other friends have helped out this evening. One of her guests has given a hand laying the table. He is Peter Docherty, a talented ballet and theatre designer. On the table are purple thistle-like cardoon flowers, this year’s fashionable vegetable; blue candles in ecclesiastical candle sticks; Sicilian crockery from Ceramica Blue, near Portobello Road; and massive blue Turkish glasses, from Verandah, also in Portobello.

Instead of overhead lighting (the moon is on low wattage tonight) there are garden flares and about 100 candles ‘twinkling magically’ on the stone floor.

There’s one other guest who has lent a hand. He’s Henry Crichton-Stuart who, having once been aide-de-camp to the governor general of Rhodesia and Nyasaland (Malawi), uses his diplomatic skills to help Clarissa organise the place settings. He’s also a cousin of the Marquis of Bute and has flown down from Bute, where his family has been since the 10th century, just for Clarissa’s dinner.

In addition to the help from her guests, Clarissa has employed her friends, Henrietta Palmer and Mel Watson, to waitress. William Morland provides the background music, fiddling right through the dinner party for a mere £30.

And what of the other guests? Queen Victoria and her son, Prince Edward, appear to have been invited. They are Alice de Mellet de Bonas and her quietly charming son, George. Alice, 72, is the vegan version of Queen Victoria. Five years ago, following the death of her Czech lawyer husband, she decided to dress up as Queen Victoria and ‘open things’. Alice is apparently descended from Queen Victoria (via Queen Victoria’s father). Tonight Alice, gentle and enchanting, is off-duty and whispers she’s wearing an M & S dress. It’s black velvet with lace lovingly added by hand. Another guest is the food writer, Claudia Roden, elegant in Jean Muir jacket and navy silk culottes.

Novelist Jane Barry bursts into the garden resplendent in very red hair and a black dress she describes as ‘a piece of sculpture’. She is covered in ethnic jewellery and complains loudly about ‘a pair of very uncomfortable shoes’. Once calmed down, she talks about her forthcoming novel, Hungry, on which Clarissa was ‘food adviser’.

Last to arrive on a financial high, is about-to-be-bond-salesman Adrian Braimer Jones, whose main claim to Clarissa’s affections ‘is that he keeps bees’.

He immediately tackles Clarissa’s cousin, Peter Thompson, about the Royal Family. Peter wrote the unauthorised biography of Robert Maxwell and has a book coming out on Fergie. ‘She’s much more likeable than Robert Maxwell,’ is all he will reveal, drily.

Over drinks, Lady Mary has a wonderful conversation about wasps not communicating. She, like Adrian, is a bee-keeper. Peter Thompson talks about Alice’s childhood in Ireland and how she married a diplomat. Pre-dinner drinks are mineral water or Taittinger NV champagne. Six of Clarissa’s guests are teetotallers, being reformed alcoholics.

Tonight the menu is completely English. The starter is in honour of Henry: 13th century herrings ‘in the fashion of Bute’ – herrings filled with hard-boiled eggs and potatoes, served with a green sauce. The fish come from Selfridges. The accompanying wine is a white Burgundy, Pernand-Vergelesses 1987.

Then there’s an Elizabethan main course, delicious roasted loin of veal stuffed with its own kidneys, served with gooseberry sauce. ‘Leopold Bloom loved to eat the inner organs of animals,’ Clarissa is heard to utter when this dish arrives. The meat comes from Quatro Bello in Camden Town. The main course is accompanied by Staton Hills Cabernet Sauvignon 1987, which has just won the All America Gold Medal 1992, although this will not be officially announced until November.

The vegetables accompanying the meat are cardoons poached in beef stock; hot buttered watercress, the Victorian way of doing it; carrots pureed with lovage, a medieval dish; asparagus pease, an Elizabethan recipe in which asparagus tips are cooked with butter and mint; plus new potatoes. The vegetables, apart from the cardoons from her country garden, all come from Portobello market.

Clarissa freely pronounces herself ‘cardoon obsessive’, she grows these unusual vegetables in Lincolnshire and has spent the last four years trying to promote their reintroduction to England. She sells them to order from Books for Cooks in Blenheim Crescent.

Just in case this herbivorous banquet proves insufficient, Clarissa has catered for her only vegan guest with a superb concoction of smoked tofu, aubergine, tomato, mushroom and coriander.

This feast is followed by raspberries with mouthwatering Cornish burnt cream, a 17th century recipe of layers of egg custard and clotted cream. There isn’t a grill here, so Clarissa appears – flaming blowlamp in hand – and proceeds to brulle it at the table, a 20th century way of doing it. Because it is an English meal, there then follows a savoury: a little potted lobster with clarified butter and mace.

Over dinner, Jane talks about matters New Age and psychic. ‘Archdeacons are generally not renowned for their panache,’ she is heard to say. Then follows a conversation about university degrees and how they bear on success in life.

Peter Docherty utters: ‘Three jumbo jet-loads of people die a day from nicotine-related illness.’ He has just given up smoking. Claudia and Lady Mary talk about the pressure to have A Significant Other in life. Then there is conversation about George’s job and the day he had to get on a plane at Gatwick in full costume.

Clarissa has been cooking all day. She cooked the dishes that needed to be prepared in advance at home, and the rest at Lady Mary’s. Catering in someone else’s home is easy for her, ‘after, all I did it for a living’. She entertains fortnightly – intimate non-al fresco dinner parties in her own home – and only uses Lady Mary’s sky-high dining room four or five dry evenings a year.

The food cost about £150, the wine £145, the help (excluding fiddler) £80. The meal was an historic and gastronomic triumph. It is agreed that Clarissa, clever and wildly generous as ever, has done it again. Blue Turkish glasses of water and champagne are raised in a toast.