Calling a Unity C# method that returns a value from Android/Java

I am developing an Android plugin for Unity and I am wondering if there is a way in the Android code to call a Unity C# method that returns a value and get this value.

Of course this will not work but is there a way, tips, tricks to achieve something like this:

 String myReturnedString = UnityPlayer.UnitySendMessage("MyGameObject", "ReturnThisString","hello");

 

Many thanks for your help.