Yum! Your seitan looks really good, too. How fortunate for you to have been able to find a roaster. I could have sworn that I saw on Whole Foods facebook page that they freshly roast hatch chillies. Then again, I might have just dreamed that up!
I haven't seem them at Whole Foods, but I know Food City and Arribas Mexican Restaurant do them.
The tacos were yummy. I used the seitan from Robin Robertson's new slow cooker book. Fresh from the Vegan Slow Cooker.