Mumbai, Nov 6 (IANS): Filmmaker Shoojit Sircar says Amitabh Bachchan is one of the most fascinating actors to work with.

The two have worked together on films such as "Piku", "Shoebite" and, most recently "Gulabo Sitabo", which also stars Ayushmann Khurrana.

"Since I have worked with both of them earlier, somewhere down the line, there is trust, bonding, and comfort between us, and that has grown slowly and matured. Of course, it is a creative process, and we keep challenging each other all the time."

"We challenge Mr Bachchan, and he challenges us. That is very important for that good, healthy working relationship. The vision of the film needed the chemistry between these two people to be crackling. It took a little time. If you work with Mr Bachchan for the first time, it does take a little time to get past that aura and in the beginning, that hesitation was there with Ayushmann and then it became fine. Mr Bachchan also made him very comfortable. In fact, he's (Big B) never intimidating, he's very easy. He may look like he isn't easy, but on set he's absolutely a director's actor, and also one of the most fascinating co-actors to work with," the filmmaker added.

"Gulabo Sitabo" released this year. Talking about the film, the director said: "It's a satire on very simple people who are struggling with their lives every day. There are these two characters -- Banke (played by Ayushmann) and Mirza (played by Bachchan) -- and also many other characters. In this film, I have explored a world which is an absolutely new and challenging world for me. I've not ventured into these characters and this space before. I wanted to present Lucknow with a new visual feel, which the audiences have appreciated."

"Gulabo Sitabo" will air on Sony MAX.