Advance Reporting on Next Step text field not updated in the last 30 days

Good morning,

Hoping someone can help here:

I am looking to report on a field in our opportunities module called  "next_step" this is a simple text field but I want to see a list of open opportunities where this field has not changed in the last 30 days - Is this possible I'm guessing this needs to be done through the advance reporting? Please help!