By Tom Brook
Park City, Utah
Sir Ben Kingsley is winning praise at Sundance for his portrayal of a pot-smoking psychiatrist in a coming-of-age story called The Wackness.
The film is set in New York in 1994 and chronicles the adventures of a middle class pot-dealing teenager who pays for his therapy sessions by handing over marijuana to his psychiatrist.
"He's probably quite a good therapist in theory," says Sir Ben, "but he doesn't apply any of his healing tenets to himself because he's an addict."
As the story unfolds there is a reversal of roles as the teenager - played by Josh Peck - helps Sir Ben's character mature.
As Sir Ben sees it: "It's a young man, an adolescent, that forces me to face myself and grow up. In turn, my gift to him is that he also has to go out into the world, into the big marketplace, and be honest to himself.
"So we both save each other eventually. But it's a very funny journey along the way."
Sir Ben has delivered some indelible portrayals in his five decades as an actor - from his Oscar-winning role in Gandhi in 1982 to his scene-stealing role as ruthless gangster Don Logan in Sexy Beast in 2000.
The actor says he is drawn to re-invention: "It's the biggest joy for me."
Mary-Kate Olsen's character is another drug buyer in the film
He maintains he is drawn to doing different characters because it helps him to continue to reach audiences.
"I won't do that by playing the same person over and over again. I'll do that by empathizing with as many human conditions as possible until I can't do it anymore."
Although the film is nicely shot - and the performances strong - there is plenty of drug taking in The Wackness which could lead to a restrictive rating which would limit its commercial prospects.
One of the film's weaknesses is that some of the depictions do not quite ring true. Too many rough edges have been smoothed out. The picture, while not glossy, could have done with some more grit.
According to Sir Ben, more than one film company has expressed an interest in buying The Wackness for distribution.
The film may have won praise at Sundance, but positive responses at the festival can be a notoriously unreliable guide to how a film will perform in the outside world.
From Sir Ben's point of view, The Wackness has given him the opportunity to add one more great portrayal to his illustrious career.