I've always like Cracker Barrel. They are the epitome of comfort food. Although not particularly the healthiest fare, they do have some offerings for people with allergies and food sensitivities. While I've never personally had to deal with their managers, I've read post after post of testimony by customers who have nothing but good things to say about how their managers have accommodated their dining needs. Allergy Free Please has a great personal experience posted with food options for various allergies. My Gluten Free New Jersey contacted Cracker Barrel to inquire about their gluten free menu items and got a detailed email from them, which they included on their website.
I had a hard time finding any sort of nutritional information, allergy information, or ingredients on their website, but you can contact them for additional information. They seem to be responsive.