Who watches the watchmen? When it comes to Jewish schools, that job falls to Pikuach, the Board of Deputies' inspection service.

Since it launched in 1996, in response to the UK statute that schools of a religious character be subject to Section 48 inspections, the organisation has cemented itself as the stamp of approval for Jewish education.

Almost 20 years and more than 160 inspections later, its work is essential - especially in the wake of Birmingham's Trojan Horse scandal.

While certain sectors of society decry faith education, Pikuach works to ensure that all 49 voluntary-aided Jewish schools are held to account.

But little is known about the inspection service's extra undertaking: alongside its training of Jewish inspectors, it also prepares members of the Sikh community to carry out their own Section 48 inspections.

"We've been training them for four years now," said Pikuach director, Jeffrey Leader. "It began when a leading Sikh educator, Ranjit Singh, asked us if he could sit in on training sessions.

"He enjoyed it, so I suggested working together. We saw it as an opportunity to provide insight into another faith and look at common issues. It wasn't to tick any multicultural box."

This year, the inspection service has been busy training 10 new inspectors - six Jewish teachers who will be surveying Jewish schools, and four who will do the equivalent inside the UK's growing number of Sikh schools.

Last Monday, the group met at Beit Shvidler Primary School, Edgware. Together, they critiqued pupils' work, debated situations, and heard from Mr Leader, as well as Pikuach consultant Sandra Teacher and chair Joan Jacobs.

"This has been a great eye-opener," said Mandeep Singh, Year Five teacher and head of Sikh studies at Khalsa Primary School in Slough. "Sharing ideas helps us make improvements.

"We're still in the beginning stages in terms of Sikh education in the UK, so it's useful to visit Jewish schools. Seeing how they teach Hebrew is a good model for teaching Punjabi."

Fellow teacher Baljinder Kaur Khela agreed, saying that observing Kodesh studies was instrumental in shaping their methods for inspecting the teaching of Gurmukhi, Sikhism's ancient script.

"We're both small communities, so it can be hard to be impartial," she said. "But we know we have to be, as we are ultimately there for the children."

Anthony Woolfson, head of the Charedi Tashbar Primary School in Edgware, said the training had been "very interesting and useful.

"I've observed lessons alongside my Sikh colleagues, and it helps you see something with fresh eyes," he said.

"We have also recognised our similarities, like how both our kids start the day with prayer. And, of course, both our parents have high standards."

As for Pikuach's work inside Jewish schools, Mr Leader stressed his commitment to training "really excellent inspectors" - who make up to six school visits every year.

"You have to have the credibility of being a good practitioner," he said. "But above all, you have to be able to make judgments on what requires improvement.

"That can be hard for teachers, especially in a community where you're likely to know the school. That is why we train them up."

With more Jewish schools being founded than ever before, Pikuach's work is set to be increasingly vital.

That way, the community can ensure that, when an inspector calls, he or she will be ready for the task at hand.