The U.S. Ambassador to the UK will cook up an old family recipe to open the fifth World Curry Festival in Bradford tomorrow.

Matthew Barzun, appointed to the post on August 1 last year, will give a demonstration of a dish originally cooked by his grandmother, 'Mother's Curry Sauce', during the first day of the event in City Park.

The festival, which will include various food stalls and culinary masterclasses, is returning to Bradford for the third time this weekend, and Zulfi Karim, founder of the event, said having Ambassador Barzun on stage to give the first cookery demonstration "spoke volumes" for Bradford's reputation as an international curry capital.

"We wanted to bring the US to Bradford via a love of curry, and I think attracting chefs and guests like the ambassador allows us to claim that Bradford truly is the curry capital of the world," he said.

"Food is what brings people and communities together, it unites people, and that was the original thinking behind the festival.

"We were really interested in the historic spice trail, from Asia into Europe and then across to the Americas.

"We wanted to reach out to the US and find out more about their culture and communities through a mutual appreciation and understanding of food."

A former internet pioneer with CNET Networks, Ambassador Barzun previously served as U.S. Ambassador to Sweden from 2009 to 2011, and was involved in U.S. President Barack Obama's election campaigns in both 2008 and 2012.

Alongside officially opening tomorrow's festivities, he will also speak at the Curry Festival dinner, meet members of Bradford Council, hold a question and answer session with students at Bradford University, and speak to sixth formers at Belle Vue Boys' School during his visit to the district.

About 30,000 visitors are expected to descend upon City Park for the three-day festival, which starts at 11am tomorrow, with new attractions including the Junior Curry Chef of the Year competition, the chance to learn to cook a curry with a team of professionals at the World Curry Festival Cooking School, and Poetry in the City, a collaboration with the Ilkley Literature Festival.

Visit Bradford, the tourism team for Bradford Council, will also be starting tis 2014 bid to retain the Curry Capital of Britain crown during the festival, asking curry lovers to build poppadom towers and vote for their favourite restaurants in the district's bid to win the title for the fourth year running.

Entry to the festival is free, but some events are ticketed, with a full programme available at worldcurryfestival.com.