Ok. Just remember there are many ways to do this.
Also remember, that a stroke will have rounded corners. If you want sharp corners, you will have to convert the text into a shape and use the stroke features in the shape tools menu bar.
But if you want to use a stroke, here's how I did this. You can also use the expand feature. Someone else may have a better idea.
Once you have your layers, we need to create a selection of the stroke so that we can mask the green layer.
Create your stroke using the layers style. Color does not matter.
When done, right click the FX in the text layer to bring up this menu.....
Select 'Create Layer'.
This will separate the stroke from the Layer Style to it's own layer.
Turn off the new 'Text's outer stroke' layer.
Turn off the Text layer as well.
Now highlight the green layer.
Cmd/Cntrl + click the 'Text's outer stroke layer' thumbnail to make a selection from it.
Now add a layer mask to the green layer. If it's backwards, select the mask and just hit Cmd/Cntrl + I to invert the maksk.
Turn your text layer back on.
But I can't leave without asking, why not just make the stroke around the text the same color as the blue layer?