Kwame Kwei-Armah is one of British theatre's most exciting creative leaders. Currently the artistic director of London's Young Vic, he has had a successful career as an actor, writer and director on both sides of the Atlantic. He came to fame playing paramedic Finlay Newton in the BBC drama Casualty, and his groundbreaking play Elmina's Kitchen was one of the first by a black British writer to be staged at the National Theatre and in the West End. In his first two years at the Young Vic, he has programmed a run of sell-out shows, including Death of a Salesman, Twelfth Night, Tree and the controversial Pulitzer Prize-winning Fairview. As the Young Vic celebrates its 50th anniversary, Alan Yentob hears how a young Southall boy called Ian Roberts became the artist Kwame Kwei-Armah.