If you don't have dried chiles, just add extra spices: ie, more chile powder, cumin and/or coriander... and/or a diced chipotle from a can of chipotles in adobo would be a nice substitution.
I used Muir Glen's fire roasted tomatoes with green chiles, but regular fire roasted tomatoes would be fine. (Diced plain tomatoes, in a pinch, would also work).
This one tastes great (maybe better) the second day - make a big batch and store leftovers in the fridge for 2-3 days, and in the freezer beyond that.