"Tom gives 100 percent in every department all day long. He's happy. He's buoyant. He's present. It's mind-boggling that this is his second time directing, and he has it down. He can shape-shift from acting to directing. It's pretty impressive," Roberts said in an e-mail interaction.
Hanks has not only directed the film but has also produced and written it. Distributed by Universal Pictures, the film is about a middle-aged Navy veteran Larry Crowne (Hanks), who after losing his job at a retail chain tries to change his life by going back to college. In his public-speaking class, Larry gets attracted to his teacher Mercedes Tainot (Roberts), who is herself upset with her husband.
"The story is charming, yet topical, for so many of the characters who are losing faith and trying to cope by rediscovering themselves. I was intrigued by it all, especially Mercedes and her drinking problem," she said.
"As an actor to be able to play that, it is so fun and heartbreaking and challenging. She (Mercedes) has pickled herself into this cocoon of an unhappy life. So without hesitation, I called Tom back and said I would hitch my wagon to his," she added.
Roberts started her Hollywood career with 1987 film "Firehouse". However, she became a star after playing the lead in 1990's romantic comedy "Pretty Woman".
She won the Academy Award for Best Actress in 2001 for her performance in "Erin Brockovich". Roberts is known for her films "My Best Friend's Wedding", "Mystic Pizza", "Notting Hill", "Runaway Bride", "Valentine's Day", "Ocean's Eleven" and "Ocean's Twelve".
Born to Baptist and Catholic parents, the 43-year-old actress started practicing Hinduism in 2009 after she visited India to shoot for her film "Eat, Pray, Love".
"Hinduism is something that I'm very intrigued by and very interested in. Along with my husband Danny Moder and our three children, twins Phinnaeus and Hazel and Henry - we go to temples to chant, pray and celebrate," said the actress, who loves "Indian spicy food".
"Shooting in India was an enlightening experience for me. My children love India. Hazel said when she grows up, that's where (India) she's going to live," she added.
Currently Roberts is working on Indian director Tarsem Singh's "Snow White" and the actress says, "His version of the Evil Queen is just going to be so fun."