Preheat oven to 375 degrees. Thaw broccoli and squeeze dry with paper towels. Combine all ingredients in a large bowl except for chicken, bread crumbs and butter. Fold in cubed chicken. Pour mixture into a 9x13 baking dish.
In a small bowl, combine melted butter and bread crumbs. Sprinkle evenly over chicken mixture. Bake for 1 hour.