A casserole dish full of stuffed enchiladas smothered with a tangy chile sauce is a sure winner, whether served as a family meal or taken along to a party or potluck dinner. The typical enchilada is a corn tortilla filled with meat, cheese, and a variety of other ingredients. Mexican enchiladas are usually assembled in a baking dish with a flavorful chile-seasoned sauce. Cheese is sprinkled over the sauce layer and then the casserole is baked until hot and bubbly. This tasty chicken enchilada casserole recipe is made with diced, cooked chicken and a sour cream sauce with green chile, mushrooms, and seasonings. Start this casserole about an hour before serving time. The enchiladas are baked on a layer of sour cream and topped with shredded cheese.