The Savoy Grill, London, 1963 - a 21-year-old former debutante sits nervously opposite an imposing businessman. It is a significant occasion, her first meeting with the man about to become her father-in-law.

"Tell me, my dear," he asks, "did you have much trouble at school, being Jewish?"

The man is Jock Luard. The young woman is Elisabeth Longmore, daughter of Wing Commander Richard Longmore, who was killed in action when his daughter was a child.

"Trouble?" she replies. "No, it wasn't an issue." She points out that she was brought up to identify with her father's Anglican faith.

Jock Luard presses on regardless. "It must have been lonely for you not going to church with the other girls."

Despite his discomforting manner, Elisabeth feels her nervousness easing. This is partly due to the belated arrival at the table of her fiancé, Nicholas - product of public school, the Guards and Oxford. But it also probably has something to do with the familiarity of the surroundings. Elisabeth Longmore has eaten often at the Savoy with her maternal grandparents - Bertha and Edward Baron, heirs to the Carreras tobacco fortune. Indeed, the maitre d'hotel greeted her by name, and she has ordered her "usual" - smoked salmon. As this arrives, her future in-law smiles and reassures her, "I have nothing against the Jews, many of them fine people, I've no doubt. I wouldn't want you to misunderstand me."

Almost for the first time, she feels the force of a strong inner identity. "I understand you perfectly," she responds. "You mean that all Jews have curly hair, hooked noses and are greedy with money."

It was a pivotal moment, the food writer, novelist, illustrator and broadcaster Elisabeth Luard now recalls. "I was really rude and really surprised at myself. I suddenly heard very clearly what Nicholas's father was actually saying." And, she maintains, she has felt buoyed by that Jewish identity ever since - usually in the most unpropitious of circumstances. "I think that one very Jewish trait is the ability to see where the bullshit is," she says.

When she married Nicholas Luard 45 years ago, he co-owned Private Eye magazine with the comedian Peter Cook, with whom he had also set up The Establishment Club in Soho. In 2004, Nicholas died as a result of cancer of the liver, a legacy of years of heavy drinking. The turbulent nature of the marriage can be gleaned from the sub-title to Elisabeth Luard's new book: My Life as a Wife: Love, Liquor and What To Do About the Other Women.

"From the outside," says Luard of her 41-year marriage, "it might easily seem that it did not work, but it did." This, she says, was because, for all her husband's long absences - with amenable women, irresponsible chums, or in pursuit of impetuous schemes to make money or save the environment - theirs was a love match. But then, as she writes in My Life as a Wife, "true love was never a match for the bottle".

Despite this, Luard refuses to take up arms against alcoholism. "I am not by nature a disapprover. Lots of things wreck lives. I didn't really notice how bad Nicholas's drinking was becoming. In those early days, everybody drank, especially someone who was a writer and a night-club owner. As a young man, it didn't seem to affect him that much. He was very athletic, running marathons at 50."

Nicholas Luard certainly was an exceptional individual. He produced a number of well-received novels and travel books and it was he, along with Chris Brasher, who established, against a wall of opposition and scepticism, the London Marathon.

The Establishment - the night-club to which his widow refers - was the legendary home of '60s satire, and much else. One of many eyebrow-raising episodes in her book reveals Peter Cook's homosexual side. Others involve the club's notorious star turn, the Jewish-American pioneer of profanity, Lenny Bruce.

"Lenny was brilliant. He was saying things others dared not say. The Establishment regulars were funnier, in terms of belly laughs, but with Lenny it was a learning process. Lenny and Nicholas were very fond of each other. Lenny took a tape recorder into court when he was up on a charge in San Francisco and played the whole thing over the phone - collect - to Nicholas, in the middle of the night."

Bruce died of a drug overdose in 1966. Eight years later, Dustin Hoffman portrayed him in the film Lenny. "Nicholas went to the movie," Elisabeth Luard remembers, "and left in the middle in floods of tears. An usherette said: ‘What's the matter, dear?' He felt he couldn't say he knew Lenny Bruce, and came out with: ‘My cat died'! Nicholas couldn't stand cats. The usherette said, ‘I had a cat. I know how you feel.'"

Another singular Jewish character who figures in Elisabeth Luard's story was the brilliant, self-taught botanist and biologist Miriam Rothschild, for whom Luard worked as an illustrator. "She was fantastic - she gave me the confidence to write. She said, in relation to a Nobel Prize winner: ‘You're not quite as clever as her, but you'll do.'"

Miriam Rothschild knew Luard's Baron grandparents. "The English Rothschilds were a dull lot compared to them," she told her. The founder of the dynasty was Bernard Baron, who arrived penniless in Britain in the 1880s and went on to make his fortune through cigarettes. Quite a fortune it was, too. "I don't know exactly how much was there," Luard's mother once told her, "but I can tell you it was more than Hannah Marks had," referring to the daughter of the founder of Marks & Spencer.

Unlike her glamorous grandparents, with whom the young Elisabeth would stay each summer in Monte Carlo or Paris, her mother rejected her background. She did marry Elisabeth's non-Jewish father under a chuppah, but quickly dropped all semblance of Judaism. After her husband's death, she married a career diplomat, had little to do with the two children of her first marriage, and eventually left her fortune - much reduced by her own father's gambling - to the children of her second.

"As a child," says Luard, "I used to go with my grandfather to the Liberal Jewish Synagogue in
St John's Wood, but my mother became increasingly antisemitic. The view was taken that my brother and I were the Jews and the other two were not. Occasionally, I would point out that this was absurd because we shared the same mother."

In her book, Luard describes three very distinctive losses. Principally, she is concerned with that of her husband, vividly detailing heroic efforts to retain dignity amid squalor and decline.

She writes movingly, too, of the death of her journalist daughter Francesca, dealt with more fully in a previous book, Family Life. But she also conveys the cold, detached ending of her mother's life, her feelings towards her unresolved. "This is the hardest thing to come to terms with," says Luard. "An unloved child feels it must be something to do with her. Writing helped me with Fran's death. But I have to come to terms with this some other way."

There is a lot of pain in My Life as a Wife, but overall it is a celebration of life, second nature to a professional cook and lover of food: "My own Jewishness certainly incorporates a desire to have everybody sitting down around a table to eat the food that I've prepared. I take a huge pleasure in that," she says.

My Life as a Wife is published by Timewell Press at £16.99