update page displayed to user between processing steps

I have an app with a section that performs many steps of processing after collecting information from the user.

I would like to update the user on the progress of this process so the user does not think things have locked up.

If I was driving this process from javascript, it would be easy to do this with ajax, but I am doing it from a controller.

I had thought about each step having a controller and calling the next controller in sequence. However, I don’t know how

to update the users screen between steps.

Any ideas?