How to update underlying TabbedPage from a Modal on pop?

Hi, so I have a Tabbed page, 1 of those tabs has a ListView page. Top right I have a toolbar that pushes a Modal which is a completely different page. I want to do an action on that Modal, which will then pop it back down, how do I tell the Tabbed page ListView to update?

I am using Rx but I guess it will be similar/same?

Thanks