Allergies are marked on the menu, but there's not a lot of options without gluten.
You can choose to keep the grill gluten free and only pick the meats without sauce. There's a couple like: lamb, chicken, duck.
For celiacs I recommend to be careful. I'm not sure how the ingredients and meats are handled in the kitchen.
— Not at all
— Gluten-free items are marked on the main menu
— Not Much/None
— Below Average