When Aaron Vallance booked a place at an East London supper club, he expected little more than a decent meal and inspiration for his fledgling food blog.

Nothing could have prepared him for the life-affirming connection he would make with Shahnaz Ahsan, the club’s organiser and chef — a 20-something northerner of Bangladeshi heritage.

The pair exchanged friendly messages on Twitter ahead of the meeting, with Dr Vallance writing: “Just a chance I might be late. I’m a doctor, so never know what the day will bring.”

The response from Ms Ahsan “felt like a shot out of the blue”, he said later. She wrote: “So, this is a bit of a random question — but did you have a relative who was also a doctor in Manchester in the 1970s? My mother has always spoken very fondly of a Doctor Vallance."

She was referring to Dr Reuben Vallance — Aaron’s late grandfather, who had been her family’s GP for many years.

He held a special place in their hearts, having nursed Shahnaz’s grandfather back to health following a heart attack, brought on by a horrific family tragedy.

Their meeting on the opening night of Ms Ahsan’s Tiger Kitchen inspired them to share their story on social media, touching hearts — including that of Nigella Lawson.  “If you haven’t already, you have to read this,” Ms Lawson told her 2.6 million followers, tweeting a link to Curry & Kneidlach: A Tale of Two Immigrant Families on Dr Vallance’s blog.

The piece pays tribute to the pair’s grandfathers. Dr Reuben Vallance, the Glasgow-born son of Eastern European immigrants, lived and worked in Manchester. Habib Ullah — whom Ms Ahsan knew as Nanabhai — arrived in the city from what was then East Pakistan in 1956. Nine years later, he would be joined by his new wife, before starting a family on an inner-city council estate.

Dr Vallance senior, a kippah-wearing Orthodox Jew, was a constant for the Bengali restaurateur and his wife, whose specialities included everything from lamb bhuna to thick-cut chips.

Ms Ahsan, now 32, wrote: “My grandmother especially came to value his care and empathy — raising six children away from the support of an extended family unit was not easy, but the unwavering assistance, both medically and emotionally, from the family doctor meant a great deal.

"He remained an influential figure in my family’s history, being there for them, for happy or painful times alike.”

Painful was an understatement for the events of 1986, when the couple’s 13-year-old son was murdered in a racist attack at school.

“The shock rang through the entire community, its epicentre of course at the heart of my family,” wrote Ms Ahsan.

“Nanabhai suffered a major heart attack on hearing the news. My aunts told me years later that they remember the doctor being there, at the hospital, providing comfort and care when it was needed the most.

"He remained by my family’s side — not only as a medical professional but as someone who knew and genuinely cared for them all.”

Ms Ahsan, whose debut novel, Hashim & Family, to be published in April, was inspired by her grandparents’ migration, added: “It was under the doctor’s advice that Nanabhai began to keep pigeons, perhaps to give a sense of purpose through his grief.”

Dr Vallance had such an impact on the family that his name lived on in Ms Ahsan’s memory, even though she was born after her family moved away from Manchester.

The younger Dr Vallance was blown away by the recollections of his grandfather, who died suddenly in 2002 after returning home from his surgery.

“Every time I read the article I still get tears in my eyes,” he told the JC. Perhaps what struck him most was that his grandfather had not only inspired his own vocation — now 44, Dr Vallance is a consultant psychiatrist — but also members of the Ullah family, who went on to work in the NHS.

In the years after the death of Dr Vallance senior, who formerly served as president of Prestwich Hebrew Congregation, Manchester NHS Primary Care Trust set up a multi-purpose health centre in his name.

The two grandchildren have a firm friendship and hope to introduce their wider families.

Back in May 2016, at the supper club, Ms Ahsan and her Jewish husband Avi cooked up Bengali food which Dr Vallance recalls as “simply beautiful”.

According to Dr Vallance, Ms Ahsan then “related the incredible story of two families — one Ashkenazi Jewish, one Bangladeshi — who risked everything they had to flee the dark tides of history”.

He added: “Shahnaz and I both feel incredibly honoured because it’s not our story as such, but one we have been able to tell and that so many people have connected with.”

Dr Aaron Vallance blogs on this story