Walking into the restaurant to meet Stephen Graham doesn’t just feel like walking on to the set of his latest film. It is the set of his latest film. Boiling Point – in which the Merseyside actor plays on-the-edge head chef Andy Jones – was shot in Jones & Sons, a modish London restaurant with a modern British menu, 24 hours before the first lockdown was enforced in March 2020. (Or “When Big Fuzzy Bozza said: ‘That’s it now, everyone get in your doors,’” as Graham recalls.) The movie is a “oner”, a dizzying single-take drama that goes some way to conveying the hypertension of kitchen life on “Magic Friday”, the last Friday before Christmas and the busiest night of the year. Battling debts, addiction and an imploding personal life, Graham’s kitchen nightmare unfolds in real time as he serves up the food, deals with difficult customers, berates his staff, gets ticked off by a restaurant inspector, and so on.

Boiling Point is also a small slice of cinematic history. It is the first British one-take movie. (Of Sam Mendes’s war epic 1917, filmed to appear as one continuous take, Graham says: “Don’t get me wrong, as a feat it’s magnificent. But we’ve been lied to [by the media]! It’s not one shot. Why don’t they just say it’s a film of 17 really long takes, do you know what I mean?”)

Today Jones & Sons has opened just for us. We will eat what the kitchen serves in Boiling Point, our menus coming with notes on key dishes from key scenes. To make things more meta I am greeted by the real Andy Jones – the restaurant, in a hidden Hackney courtyard, is his. (Graham is keen to point out that the tribute is name only, the IRL Jones shares none of his fictional counterpart’s “issues”.) The real Stephen Graham is hidden behind him. Five-foot-five but built like a brick outhouse, he is a tower of unshaven charisma in a black tracksuit and baseball cap, humming expensively of designer scent. Boiling Point was brought to Graham by Philip Barantini, who worked with him in Band of Brothers, and who writes and directs from experience. “He was an actor and he had the odd job here and there but, you know, he fell on difficult times,” Graham says. “So he trained to be a chef. And he worked in some really big kitchens.” The result is the first film from Matriarch Productions, the company Graham set up last year with his wife, actor Hannah Walters, to tell “authentic and real” stories.

“We wanted to raise awareness of mental health issues, the amount of pressure in this industry,” he says. “And have a fair representation of what it’s like in a London kitchen. We wanted a completely diverse cast, you know? ’Cos the front of house can be considered very white, in elitist restaurants. But if you go in the back…”

Our starters arrive. Grilled mackerel with curry mayonnaise for him, salmon cured in seaweed for me.

Even given his stellar record, Graham has had quite the year. In Jack Thorne’s Help he was excellent as an early-onset Alzheimer’s patient in a care home during Covid, opposite Jodie Comer’s helpless carer. But in Jimmy McGovern’s Time, playing a compromised prison officer to Sean Bean’s floundering first-time inmate, he was astonishing. Both can take their place among the very best of what TV can be. Enraging, unmissable, inescapably harrowing dramas that show our institutions under duress and wanting, heartbreakingly so.

Graham, who broke through playing sociopathic skinhead Combo in Shane Meadows’s This is England, seems to be on a one-man mission to revive the working-class social realism of Play for Today-era telly. (Insert your own “kitchen sink drama” pun vis-a-vis Boiling Point here.) Graham bangs the table. “Yes! Thank you! Thank you!” he says, possibly out of all proportion. “That was exactly my intention. I’ve made a conscious decision, going: ‘Do you know what? Them voices that I heard on telly that made me want to be an actor, the likes of Andrew Schofield and Ian Hart and Cathy Tyson [all cast in Help], they’re not around that much. So, I’m going to spend a couple of years just doing my own accent.’”

There have been exceptions, notably Martin Scorsese’s The Irishman, playing Anthony “Tony Pro” Provenzo, opposite Robert De Niro and Al Pacino. But Graham remains largely impervious to the Netflix tractor beam.

“A lot of people have said: ‘You shouldn’t be doing this. You should be doing big movies,’” he says. “But I think British films are in danger of being a dying art, if I’m honest. Where’s the next Jimmy McGovern going to come from? It would have been very difficult for Shane Meadows to make Twenty Four Seven today.”

Because no one would take a punt on it?

“Possibly, possibly,” he says, through bites of the same venison dish that necessitates a 999 call in Boiling Point, “but one of the first things out of people’s mouths is: ‘Well, maybe Netflix’ll like it.’”

The kind of acting where Graham’s happiest is improvisation. Being given the freedom to put his own meat on a writer or director’s bones. Boiling Point required piles of it by necessity. And it’s how both Meadows and Scorsese work. Graham likes to get involved – the prison-made box that Combo uses to profess his love for Vicky McClure’s Lol in an outrageously good scene from This Is England (it’s on YouTube) was his idea. So was whacking a bowl of ice-cream across the room from under Al Pacino’s nose in The Irishman – something the cameraman and the props department were in on, but the director and actor were not. (“Did you see that, Marty? That kid frightened me!” is the anecdote Graham likes to tell on chat shows – as you would too if you’d earned Scorsese’s respect by going off-piste with some dessert.)

Still, there are plenty more writers and directors who want things exactly as the script dictates – without hesitation, repetition or deviation. Jed Mercurio is apparently one. It makes me wonder how Graham found doing Line of Duty, playing undercover DS John Corbett in series five.

“He was like that,” he says, laughing, of Mercurio. “Until he’s got me phoning him at half-ten on a Sunday night, going: ‘I’m learning this for tomorrow and it just doesn’t feel right…’”

Apart from entertaining the notion of becoming a youth worker and getting as far as passing the exams to be a fireman (you can imagine Graham being, or at least playing, either), acting is all he’s wanted to do since he was 10. You won’t be surprised to learn he’s not bothered by the fame, only that it might be to his detriment. “I worry that people will think, ‘Oh, he’s in everything.’ But I’m trying to tell stories that need to be told.”

Besides, it’s only Line of Duty that has made him feel recognisable. McClure had warned him – “I know you’ve done Hollywood but once it’s on, be prepared. It goes nuts” – and after episode one he knew what she meant.

“The next day I went to Co-op and it was on another level.”

What did people want to know?

“‘Who is H?’” he laughs.

His school careers officer told him to forget acting (“get a trade”), advice happily ignored by his stepfather, “Pops”, who took him down the video shop and rented Taxi Driver, The Godfather and The Deer Hunter. If he was serious about acting this was the stuff to aspire to. He had a freak-out in his 20s, a pile-up of family and work stuff, and in 2019 told Lauren Laverne on Desert Island Discs that he tried to kill himself – an audible bombshell. “I tell you why that was, she was such a great interviewer,” he says. “I wasn’t expecting to say any of that. I wasn’t prepared. It just came out.”

Afterwards he was inundated with thanks from people for speaking up (there were similar messages in response to his recent work from care home workers and prison staff). These days he is teetotal, practises Buddhism and meditates.

We talk a little about what sort of dad he thinks he is. One that his kids can tell anything to, he hopes. He says son Alfie is like a best mate, that they’re always getting into trouble for play-fighting and knocking a football about. And that he will encourage his kids to be whatever they want to be.

Given his own stepfather’s encouragement, I wonder which of Graham’s roles he likes the most.

“I don’t know, I’ve never asked him,” he says. “Shall we ask him?”

So he phones him up.

“Dad! What are you laughing at? Right, listen, I’m just doing this interview, with this lovely fellow, for the Observer. And he’s asked me a question to which I don’t have the answer. I’m going to put you on loudspeaker…”

“What’s the question?” asks Pops. “Well, I’m going to fucking tell you now…” replies his son.

No hesitation here either. It’s Combo.

“Combo I liked for a lot of different reasons,” Pops explains. “It was the door-opener, wasn’t it?”

It was the kind of role his stepdad had suggested his son hold out for, and the one he thought he’d blown before filming even began because he’d not yet told Meadows he was mixed-race (his biological dad and Pops are black) – Combo being an English nationalist and a racist. Meadows’s reaction: even better.

Andy Jones says he has to skip out – Boiling Point is premiering at the London film festival in a couple of hours and he needs to buy a suit. But there’s time for a quick tour of the set. If Jones & Sons found itself short-staffed, on Magic Friday, say, does Graham now have the chops to help out?

“Listen, I’d give it a go,” he says. “I’d get stuck in.”

Boiling Point is in cinemas from 29 Dec.

In the UK and Ireland, Samaritans can be contacted on 116 123 or email jo@samaritans.org or jo@samaritans.ie. In the US, the National Suicide Prevention Lifeline is 1-800-273-8255. In Australia, the crisis support service Lifeline is 13 11 14. Other international helplines can be found at www.befrienders.org