Ember return model with 2 promises

I have a route class and in the template, I use a custom grid component

{{my-grid params=this.gridParams elementId='myGrid'}}

Now, there are 2 AJAX calls to be made to populate the grid;

1. /getColumns (this column header data response is used to set some properties on my controller)
2. /getData (this body response is actually used to populate the grid with actual data and is actually computed to gridParams)

These

I was reading the guide on "The Router Pauses for Promises" http://ift.tt/1P2uvzC

However, this is for a single promise/ajax call.

How can I make it work in my case ?