Catered for a work lunch, when I reached out via email, I was sent their list of food offered with GF and vegetarian options. Their chicken gyro meat is GF, but not the beef/lamb. Only rated four stars because while I was fine after eating it, I just don't find there a lot of variety for protein options.
My employer ordered food from Zakia for a work retreat. They do have GF items on the menu. I emailed them to check if they could make a meal to a celiac standard of cross contact prevention- separate from other food, throughly cleaned pans and utensils, etc. and they were very accommodating! I had chicken, salad, grape leaves, and falafel. They packaged it separately with my name marked on it. It was delicious!