Joan Chen, whose critically acclaimed directorial debut, “Xiu Xiu: The Sent Down Girl,” opens May 7, is returning to the other side of the camera for two new roles.

First up, Chen will star along with Lou Diamond Phillips and Cara Buono in the fact-based “Prince of Mirrors” for Showtime Networks family division. She plays a high school teacher who helps the school janitor get an education so he can keep his job. Robert Munic directs from his own screenplay; Wendy Finerman produces.

Immediately following, Chen moves on to the indie production “What’s Cookin’,” co-starring with Julianna Margulies, Kyra Sedgwick, Mercedes Ruehl and Alfre Woodard in a film that focuses on several families in the same neighborhood celebrating Thanksgiving. Jeffrey Taylor produces and Gurinder Chada directs from his own screenplay.

Chen is repped by the Rigberg-Roberts Co. and her new agents at Innovative Artists.

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Tony Shalhoub, last seen with John Travolta in “A Civil Action,” has signed to star with Tim Allen, Sigourney Weaver and Alan Rickman in the DreamWorks comedy “Galaxy Quest.”

In the film, directed by Dean Parisot and written by Robert Gordon, Shalhoub plays an actor portraying a crew member of a space ship on a science-fiction TV show.

Shalhoub is represented by Mary Goldberg and United Talent Agency.

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Elizabeth Mitchell has signed to star opposite Dennis Quaid and Jim Caviezel in “Frequency” for New Line.

Mitchell recently wrapped Neil Labute’s “Nurse Betty” for Propaganda with Chris Rock and Rene Zellweger.

Mitchell’s “Frequency” deal was brokered by Seven Summits and Paradigm.

— Compiled by Vanessa Torres