Lamb stew meat saves time, but you can cube any boneless lamb (leg of lamb).
If you have made a batch of my Mexican mole spice blend, use about 1 1/2 tablespoons in place of the cumin, cocoa, ancho, and cinnamon.
I keep ancho, chipotle, and New Mexico red chile powder in my pantry. You can use any of them. I don't think generic "chili powder" is a good substitute as it's a spice mix and will throw off the proportions.
Beer is not "gluten free" unless it's labeled as such. Substitute additional broth/stock if gluten sensitive. As I mention in the post, I have used both chicken and beef. If you've got turkey, I think that would be fine too!
Nutrition is an approximation and for reference purposes only!