Usability testing dashboard

I want to usability test the current dashboard before I start any designs to understand how current users are using it and what are their pain points. In the past when I have done such testing I have been able to give the user a task and see what issues they have encountered to complete it.

However, with a dashboard I am struggling to think of any task I wish for them to complete as it is all on the one page.

When the usability test just involves one page and not much interaction to record, do I show the user the design and ask questions to understand their behaviour or is there another aspect I can include in the test that will give me further insight into their behaviour?