After the success of his bittersweet love story 'The Lunchbox', director Ritesh Batra is writing his next film which is again set in Mumbai.

'Lunchbox', starring Irrfan, Nawazuddin Siddiqui and Nimrat Kaur, garnered much critical acclaim both in India and abroad, except for the controversy over it being overlooked as the Oscar entry from the country last year.

Batra has put the disappointment behind him as he feels film bodies and old guard in India will take time to understand how global cinema world works.

The director says his entire focus is now in telling stories that are rooted in India but are universal in their appeal.

"I am writing my next film. No matter how big your last success was, the writing does not get easier. This process is really important for me. I want to begin shooting my film by next year, probably mid-2015. It is going to be a drama that is set in Mumbai," Batra told PTI.

The director does not want to divulge the cast but says he would love to work with his 'Lunchbox' team again.

"One of the reasons why the film worked was the wonderful collaboration between these three actors. I would love to have any excuse to work with them again. But I am writing so I can't say much about the cast," he says. Actress Nimrat Kaur bagged American TV drama 'Homeland' after playing the role of a lonely wife in Batra's film. The director thinks she is one of the best parts of the espionage drama.

"I think she is the best thing about 'Homeland', she is really great in it. She is a tremendous talent and she gave so much to the part. It was just a matter of time before she got noticed for her talent. I am glad that it was through my film."

As far as 'Lunchbox' is concerned, Batra says the film has been a blessing for everyone involved.