Bring water to a boil, add noodles, and then drain when noodles are cooked to desired texture (see "Substitutions" section for noodle options)
Cook Chicken
Bake, boil, or cook your chicken any way you prefer -- or use leftover chicken (see "Substitutions" section for chicken options)
Casserole preparation
Preheat the oven to 400°F/200°C
Grease an 8-inch casserole dish
In the casserole dish, add the cooked egg noodles, cooked chicken, frozen peas and carrots, cream of chicken soup, sour cream, and milk or water, and then set aside
Crunchy topping (optional)
Mix together the breadcrumbs, melted butter, dried herbs/parsley, pepper, and salt in a bowl
Sprinkle the top of the casserole with the breadcrumb mixture
Cooking
Bake the casserole uncovered for 15 – 20 minutes, or until the top is bubbling (and if using breadcrumbs, until they are toasted)