First, steam some broccoli florets or microwave a bag from the frozen section, then spread out in the bottom of a casserole dish, add some shredded cheddar cheese to the top of the broccoli layer. Second - Mix these three ingredients together: 1 can of cream of mushroom soup, 1 cup of sour cream and 1 cup of chopped or shredded left over chicken. Third, pour the cream of mushroom mixture over the broccoli and cheese layer. Forth - add more shredded cheese. Fifth - crush a whole tube of ritz crackers and spread over top. Add a few pats of real butter to the top of the crumbs. Bake at 350 for 30 minutes.