An article in the International Herald Tribune compared the quality of her performance to the likes of Judi Dench and Maggie Smith.
Another role that she played to great acclaim was Tessa in The Girlfriend Experience, which she performed at the Royal Court Theatre and the Young Vic.
Chazen starred as Ruth in the stage play Calendar Girls from November 2009 to January 2010 at the Noël Coward in Leicester Square, during which time she was diagnosed with breast cancer and had to withdraw halfway through the run in order to start treatment.
She made a full recovery, and returned to Calendar Girls in the same role for a national tour at the end of 2010.
In 2014, she appeared in the Sherlock episode "The Sign of Three", and on 19 June 2014, it was announced that she would be joining the cast of Holby City.