They have a GF menu online. I️ always get the chicken and corn tortillas. They do have a lot of options. I️ don’t know how knowledgeable the staff is, but I’ve never asked and have just ordered from the GF menu. I’ve seen the chicken prepared, and I️ think if you get chicken and corn tortillas, there is little risk of cross contamination. I’ve never felt sick after eating there. I️ have celiac disease.
The thing is with a lot of these food chains is that there will be cross contamination, so if you are diagnosed with celiac, I would stay away. The rice has has traces of gluten in it, but the chicken is GF as far as I know. If you do not have serious gluten issues, get the chicken bowls or salads.