"I could not leave," he says to me, scooping up some hummus with a torn-up piece of bread.

"It was so different then. Just the damage, the violence, the fights, the complete disrespect ... Kids breaking windows and kicking doors. It was senseless. You were forever watching."

Evidently, things have changed.

For starters, here we are at 12.30pm on a Wednesday at Jasmin1 in Punchbowl. I had approached Dib several weeks earlier, right in the middle of Ramadan - the most inopportune time possible to ask a Muslim bloke to lunch. He politely laughed off my ignorance and now, days after the fasting finished, we find ourselves ploughing through a veritable feast.

Plates of kibbeh, skewered lamb, chicken breast, felafel, beans, tabouli, hummus, baba ganoush, olives and pickles and a cluster of drinks all compete for space on the large table between us. Women in hijabs idle and laugh over lunch at nearby tables, toddlers shrieking in prams in the aisle, while young men on lunchbreaks rush in for takeaway. Dib is clearly a regular, exchanging warm chat with the staff, while also half the customers seem to know him.

That things have changed at the school, transformed from a notorious, rough-as-guts high school to pillar of the community under Dib's leadership, is almost folklore. Perhaps because the young principal, who took on the role when he was just 33, is such an agreeable interviewee, or perhaps because the public relishes a good To Sir With Love narrative, Dib has become as close as any public school principal in Sydney has ever been to famous. Enrolments and parent engagement at the school are up, test results are improving and expulsions simply don't happen any more.

His work at the school, and in the predominantly Lebanese south-west Sydney community, has inspired magazine articles and earned him a place in the TV documentary series Once Upon A Time in Punchbowl, saw him address last year's TED X conference and earned him a place at the table in Canberra in 2012 as the Gillard government was shaping its education policy.

It's also got the attention of NSW Labor who, at the time we sit down to lunch, were rumoured to be in talks with him for a tilt at the state seat of Lakemba. But we'll get to that over dessert.

On our way to the restaurant from the station - where Dib insisted meeting me earlier - he was greeted with an almost celebrity-like devotion by every teenage boy we passed, who - without exception - stop to shake hands. At the same age I think I would have crossed the street to avoid my high school principal.

It's the result of a morning ritual he has at the school: he and other staff stand at the gate, welcoming the boys and shaking their hands, chatting to parents and grandparents.

"It's that welcoming gesture - 'we're here for you, and whatever happens today, it's OK, we'll deal with it'," he explains.

Making the school feel more like family - a word he uses often - has been critical to the culture change Dib has tried to foster at the school.

"It took a long time to get that, but it happens by being at the gate, by coming down to the [train] station, by visiting families at home, by paying respects when they've lost somebody, by being real."

I ask how much he thinks his own Lebanese background has helped him forge this connection.

"I think it helps but, having said that, I've got some Muslim teachers who struggle there," he says. "I've got a lot of non-Muslim and non-Arabic teachers who go so well.

"I understand where [the students are] coming from a little bit more, I understand their family issues."

Being able to speak Arabic helps a lot, he says, especially with the parents and grandparents.

Dib's own parents migrated to Australia from Lebanon in 1975, when he was a toddler, and today live in neighbouring Greenacre. He grew up in a big family, his youthful energy often divided between helping out in his parents' shop and studying hard at school.

Dib jokes his dad wanted him to become a doctor- "like all migrant parents" - but his parents were proud of him for choosing to study education.

Dib's first taught in Ulladulla, on the south coast, but he says he felt drawn back to south-west Sydney in the late 1990s and early 2000s. It was a time the Sydney Lebanese Muslim community suffered heavy stigma under a perfect storm of media coverage about gangs, gun crime, terrorism and fears about asylum seekers.

"It really affected me," he said. "It sounds a bit conceited, but I didn't feel right being there when people were here doing it tough, and I thought I could have helped."

Dib is almost irrepressibly cheerful, and never more so when talking about the school and its successes, the good "vibe" they've got going now.

"I love the movie The Castle," he says with a laugh. "It's the vibe," he says, quoting the film's famous line.

"It's just that - it drives you."

But he turns serious when we discuss education policy, particularly the contentious subject of NAPLAN.

He describes how deflated his students were when they first saw the league tables, in newspapers like this one, ranking schools according to their test results.

"They said, 'Sir, are we really that bad? You told us we were a good school, and this is saying we're one of the worst schools' ... it was just this collapse.

"So I got up in assembly and gave a really impassioned speech ... I said all that's important is the effort you make. And that's all I care about."

Almost every boy at his school comes from a non-English-speaking background, many arrive with little English and two thirds come from the most disadvantaged socio-economic bracket. They start well behind.

"You can't compare us to a selective school, it's just not fair," he says. "If [those schools] don't get top of the state there's something wrong."

Though the school's raw marks still tend to be well below the state average, in maths at least, students at Punchbowl are improving faster than others at similar schools – a better measure, in the view of many, of what a school is doing.

Dib's passion rises too when we talk about the Gonski plan, now in doubt in the long term under the Coalition federal government. He says the needs-based funding model that is central to the plan is vital for schools like Punchbowl, and any suggestion that the system is equal is fanciful.

"I managed to get a donation this year, of 100 pairs of shoes, that kids could wear to school," he says. "That's poverty. You wouldn't have to do that at those elite schools. It's not even on the radar."

With this background, it's easy to see why NSW Labor leader John Robertson is said to be so keen on getting Dib as their candidate for the seat of Lakemba. Dib had been approached by the Liberals at the past election but declined the offer. But he's clearly interested in the prospect of running for Labor.

"We have had some discussions," he confirms, choosing his words carefully as we tuck into our rice pudding dessert with plastic spoons.

"What I've seen in the community is that I could make a further contribution, and if I could make a contribution politically, then I reckon that would be really good. There's more to me than just the school principal."

Since our lunch, a stoush has emerged, with former premier Morris Iemma slamming the push to run Dib and not leave the decision to the rank and file membership. Bankstown mayor Khal Asfour has also confirmed his interest.

The stoush seems a tiny taste of what could lie ahead for anyone contemplating entering NSW politics, which is as dynamic and brutal as ever. I ask whether he worries about that and about the way idealistic, high-profile candidates like former federal education minister Peter Garrett seem to get chewed up and spat out.

"You certainly think about it," he says, and his face drops a little.

"But you've got to get in it. I've always said to everyone, career-wise, I respect the person who's done it, and then said 'I don't want it', over the person who stands on the sidelines and says, 'You should be doing this or this.

"I would like to think I could make a difference. I don't know what other people think."

And of course, he says, "leaving the school would always be really hard".

After lunch we end up on the same train into the city. We take a seat in the middle of the carriage, behind a group of three young boys, not from Punchbowl, who are horsing around, shoving each other, shouting and tumbling around on the blue seats. Dib's eyes follow them from the seat to the aisle as the play gets rougher. It becomes apparent that even if this man is taken out of the school it will be harder to take the school out of the man.

"Hey, boys, how about we settle down please," he says calmly, but making clear it is not a question. They stop straight away.

Dib turns to me and smiles almost sheepishly. "The principal in me couldn't help it," he says.

LIFE AND TIMES

1973: Born in Tripoli, Lebanon.

1975: Emigrates to Sydney

1995: Graduates from Wollongong University with a bachelor of arts and graduate diploma of education

1996: Begins teaching at Ulladulla High School

2002: Returns to Sydney to become head teacher of English and history at Belmore Boys High School

2007: Becomes relieving principal at Punchbowl Boys High

2009: Appointed permanent principal at Punchbowl Boys High

2009: Appointed a commissioner on the NSW Community Relations Commission