After reading bad reviews about this place, I decided to find out for myself. The food tasted terrible, and I felt sick the rest of that night. I only ate half of what I bought because of the taste. I don't know if the fish was spoiled or if the sauce they gave me wasn't gluten free even after I asked at the register. I just know I won't eat there again.
Kitchen is not very conscientious. Have used wrong sauce and given fried rice in gf orders. Hard to know until it's too late. Had to stop going to Zen due to way too many mistakes. Too bad. Also got raw chicken in stir frys due to chicken being in very different sizes pieces (but all cooked same amount of time). Mgmt not interested in fixing.
They have a printed menu with all allergens (you must ask for it, sometimes it's laying on the counter by the register). An employee also has duhrings (DH) so they seem to have a good understanding. I have never had a problem here. FYI, Most sushi/cold case items are not GF.