Moeen Ali has learned a wide range of lessons in his first three months as a Test cricketer, most obviously the greater scrutiny that turned his decision to wear Save Gaza and Free Palestine wristbands during the third Investec Test in Southampton into a major issue. But he argues that it was in the nets before the previous Test at Lord’s that he made the technical breakthrough that triggered his spectacular emergence as a matchwinning spinner, thanks to the unlikely combination of his team-mate Ian Bell and the Sri Lankan umpire Kumar Dharmasena.

At that point Moeen had made a more positive impact as a batsman, notably with the memorable last-day century at Headingley that so narrowly failed to avert a series defeat against Sri Lanka. His seven wickets had cost more than 50 apiece and just as importantly he was leaking runs at 3.7 runs per over, reinforcing the arguments of those who dismissed him as a part-time spinner and as the palest shadow of Graeme Swann.

“After the first Investec Test at Trent Bridge, where I went for quite a few runs, I sat down and analysed it and felt the need for change,” the 27-year-old says. “Then Belly took me to one side on the practice day at Lord’s and said, ‘Look, this is what you’ve got to do to be consistent in the Test side, this is what Swanny did, bowl quicker and straighter, especially on a first-day pitch.’ Then I went into the nets and Dharmasena was there and I asked him, as a former off-spinner, how could I bowl quicker without it being flat. I didn’t want to bowl one-day stuff. And he said to me, ‘Just grab your pocket as quickly as you can with your non-bowling arm.’ As soon as I bowled one ball I knew it would work. That, for some reason, allows me to bowl quicker and straighter without being flat.”

Moeen also confirms that he has shelved his doosra. “I don’t need it at the moment,” he said. The results have been stunning. In the three subsequent Tests Moeen has taken 15 wickets at an average of less than 16 each and conceded runs at only a smidgen more than three per over. He needs one more wicket at The Oval this week to equal Ray Illingworth’s all-time record in a home series against India for an England spinner of 20, having already overtaken Swann’s 2011 tally. Perhaps it would be a slight exaggeration to say that India now agree with Worcestershire’s description of Moeen as the ‘Beard that’s Feared’ but he has certainly earned their respect.

“They felt I was an easy target, a guy they could get easy runs from, which has helped me quite a bit,” he reflects. “If they attack me, now I’m bowling well, I’ve got a chance. But they’re very good players of spin. I don’t know how I’m getting these wickets but I’m happy to. I feel like I’m on top and I feel I can get players out.

“I’ve always felt I could take wickets, but it was about being consistent and getting the captain to keep me on for longer periods of time. My mentality changed after that first Test against India. At first I felt ‘they’re really good players of spin, what am I going to do?’ But then I told myself ‘as long as you’re bowling it doesn’t matter who’s batting’. Since I’ve had that mentality, so far, it’s been working.”

He agrees that earning the trust of his captain, Alastair Cook – of whom he speaks with genuine respect, saying“I have never met a mentally stronger person in my life” – has been crucial. “When I wasn’t bowling enough it was my own fault because I was leaking too many runs,” Moeen says. “I understood that. But since that net session at Lord’s I feel he can rely on me more and I like that. If I come on to bowl, he lets me have my own fields, with his input as well, and we’re getting on really well. .

“I don’t want to get carried away. But I feel I’ve taken a big step towards being a decent Test spinner. I feel like I have more control, and that my captain and team-mates can trust me. Even on a first day pitch I feel I can do my role now. I don’t want to speak too soon in case I get hammered on Friday but I feel very confident.”

Reassuringly, Moeen also remains sufficiently confident to talk about his faith, although he admits of the wristband furore: “I’ve been advised to be careful. I didn’t think it would be such a big deal. I just totally forgot I had them on when I went into bat. Obviously it all came out but it didn’t bother me one bit. To get six wickets and win a game for England was an amazing feeling.

“I have to be a lot more careful. The ICC didn’t allow me to wear them and I accepted that. I have a lot of opinions on a lot of stuff but it’s not the time and place now to go into it, especially before a Test match. Maybe later on. I wasn’t trying to be political, it was just a humanitarian thing. I’ve got a lot of positive reaction and I’d really like to say thanks to the ECB for supporting me.

“There’s been a bit of change,” he says of his life back in Birmingham as an England cricketer. “When I go to the shops I get free food and stuff now. A lot more people obviously recognise me and ask me for autographs. It’s good because I get a lot of Asian kids especially coming and asking me ‘What’s it like playing for England?’ and ‘How do people treat you?’ and that kind of stuff.

“That’s the kind of barrier I want to try and break down – that people think it is tough and will treat you badly if you’re a practising Muslim or whatever. That is the reason I like to play cricket for England – because I can break down barriers for other people and inspire kids, not just Asian kids but all kids, to play.

“Even if I didn’t play for England again, speaking to a lot of these kids I can see they’re really interested and really want to play for England, which is nice. Previously a lot of them wanted to play for India and Pakistan but now I get a lot more Asians coming up to me saying they’re supporting England. That’s what I want and that for me makes me happier than anything – a lot of people are supporting England and want us to do well.

“I was born in England, raised in England and I am more English than people think sometimes. It has never been a question that has crossed my mind. There have been a lot of people who have supported Pakistan or Sri Lanka but I have a lot of opinions about things and I have questioned why they support other countries. I think it is changing. It is probably because their parents were born in Pakistan and followed them but now the generations are born in England a lot more will support England.”

Now he is a cult hero, with the crowds in Southampton and Manchester cheering every time Cook threw him the ball. “At first I was not sure if it was because they were going to see more runs,” Moeen says with a smile explaining the pictures that appeared of him on Twitter a few days before he wore those wristbands, showing his support for the Ummah Welfare Trust in Birmingham.

“Actually that picture with that guy was when I was going to Asda with my family and he obviously recognised me and asked to pose for a picture. I was like ‘All right then,’” he says. “I do like to do charity work but that particular day I wasn’t actually doing it, I was just going shopping.”

Investec, the specialist bank and asset manager, is the title sponsor of Test match cricket in England. Visit investec.co.uk/cricket or follow @InvestecCricket