'I don't really want people to see me. I'm not into stardom," says David Suchet. What Suchet wants people to see is the character he is playing in the new production of Arthur Miller's All My Sons, not the actor who is playing him.
We are sitting in a south London studio where Suchet and the production's other star, Zoe Wanamaker, have been rehearsing the play that in 1947 confirmed Arthur Miller as a great playwright. And the character that Suchet plays in the West End revival of the tragedy is patriarch and industrialist Joe Keller, whose business partner took the rap for supplying dodgy engine parts to America's air force, resulting in the deaths of pilots - men like Keller's missing-presumed-dead son. "The whole reason I became an actor was to serve my writers," continues Suchet.
"My writers". It is not, as it may sound, a phrase that implies ownership, but one that reflects a duty of care the best actors feel towards those who supply their material.
"I became fascinated by the fact that people write to give away rather than write to be read. It's the difference between playwrights and novelists." Suchet is tucking into a carefully prepared high-protein lunch of roast chicken, nuts and ignored lettuce. "Help yourself," he says convivially.
All My Sons, which opens next week, is a play that stakes out one of Miller's abiding themes - personal responsibility, for oneself, for family and for society. But in Keller it also contains the portrait of a patriarch whose pride is stripped away until the respect in which he once wallowed turns into the kind of shame a man can drown in.
"I was going to do Death," says Suchet, referring to Death of a Salesman and the role of Willy Loman, another Miller play anchored by a manly character whose exposed vulnerability makes grown men cry. Unfortunately for Suchet, Death did not happen. Then came the call offering Sons, with Suchet's long-time collaborator, Howard Davies, directing. It is the second time in a decade that Davies has directed the play.
"It's a great role," says Suchet of Joe Keller. "And it has to be one of the 10 best plays in 20th-century in America. No actor in his right mind would say no." The sonorous voice is very different from the sinister whisper Suchet deploys when playing Agatha Christie's detective Hercule Poirot - the role which has made this son of a distinguished gynaecologist world famous. But it is familiar to those who saw his stage roles-his Salieri in Peter Shaffer's Amadeus; his George (opposite Diana Rigg) in Edward Albee's Who's Afraid of Virginia Wolf; and his Shylock, the first time in 1971 as the youngest actor to have played Shakespeare's Jew, the second time, 10 years later for the Royal Shakespeare Company.
Each of these performances - and a good few others - have been acclaimed. In fact, it is hard to find a bad review of a David Suchet stage performance - I tried and failed - which is why during David Suchet interviews journalists usually ask whether it was always the plan to turn such a prodigious stage talent towards television.
Not that there have not been notable non-Poirot television performances, too - the title role in Blott on the Landscape, Augustus Melmotte in an adaptation of Trollope's The Way We Live and more recently, Robert Maxwell, a role for which that chocolaty cello of a voice became a booming foghorn.
They are all wonderful roles. Without them there may never have been that OBE. But the assumption has sometimes been that Suchet might, deep down in his actor's soul, harbour less respect for Poirot than he does for his theatrical alter egos - George, Shylock, Caliban, Gregor Antonescu in Rattigan's Man and Boy or the professor in Oleanna, David Mamet's crunching two-hander about political correctness which Suchet starred in for the European premiere in 1995.
Most recently he provided the rock solid performance next to a shaky Richard Dreyfus (who needed prompting with an earpiece) in the Kevin Spacey-directed Complicit.
This is one of two questions that, if not haunts, perhaps harries Suchet like the unwanted attentions of Poirot fan. Not so much why a great theatre actor would turn to the screen - many have and do, and the reasons are obvious - but whether there is any regret that such huge television success has come at artistic cost. The other question is why at the age of 40 in 1986, he converted to Christianity - a decision which, despite his near-atheistic agnosticism he attached to a lifelong search "for something beyond which I could see".
Raised by his Jewish, atheistic father and a non-practising Christian mother, Suchet's childhood and that of his older brother John (the well-known television presenter) and younger brother Peter (a former partner in Saatchi and Saatchi) was completely without religious observance. The decision to convert to Anglicanism was, he has said, one that could have just as easily led to Judaism. It is not a subject he likes to talk about much. You get the sense that his rejection of stardom is not just about his commitment to the characters he plays, but about a need for privacy too.
"For my obituary there will probably be a little small picture of me and big picture of Poirot," admits Suchet. "Does it worry me? Not in the slightest. I'd love to be remembered as a character actor who brought illumination to roles in wonderful plays, and who delivered performances that made people think and rethink those roles."
So nothing here that suggests a man who is anything but happy with having the little Belgian in his life. In fact one of Suchet's ambitions is to leave the entire canon of Poirot novels - all 39 novels and four short stories - as his legacy. There are only six left to go. There is even talk of a stage version, though Suchet has yet to be persuaded that it is a great idea, he says. Then a slight pause suggests a momentary rethink.
"There has been a cost," he admits. "Because I've never known when Poirot is going to be filmed, I can't say yes to a play in a period when filming might happen."
There was one time when he did say no to the detective. It was in 1995 and ITV phoned Suchet's agent just one day too late to take up their option. In that 24 hours Suchet had grabbed the chance to do Oleanna. That conflict seems to be less of an issue now. The gaps between plays are, theatre-goers will be delighted to hear, getting smaller. Less happily for Poirot fans, Suchet does not or cannot take for granted that he will be asked to finish complete the detective books - though he would dearly love to.
"I've never known when I'm going to do another one. Not from 1988 onwards. It has never been a sure-fire thing. I'm just an actor for hire."