I'm not a big casserole fan, but this one is very flavorful and simple to make. I don't use a recipe and just scale the ingredients as I go. But as I'm often asked to provide one, below you will find measurements that you may find useful. Adjust as you prefer.
While they cook, wash and slice mushrooms. Remove the cooked chicken to a large bowl and add the mushrooms to the broth and let cook until they've released their liquids, another 5-7 minutes. Season the resting chicken with poultry seasoning. Remove the cooked mushrooms from the liquid and add to the bowl with the chicken. Bring the liquid to full boil and add the curly noodles. Cook until al dente, about 8 minutes. Using a slotted spoon, remove the noodles to the bowl with the other cooked ingredients.
Mix milk or cream with flour to make a slurry. Reduce the temperature of the cooking liquid to a low boil and add the slurry, stirring constantly to thicken the mixture. Add additional milk or chicken broth if necessary until you have a mixture that will coat the back of a spoon. Do not make the mixture overly thick. Cook for 5 minutes and season with salt and pepper to taste.
Pour over the cooked ingredients and gently stir. Use only as much of the liquid as necessary to fully coat the ingredients and reserve the left over. Add peas and stir again. Let the mixture sit while you prepare a topping. This will give the mixture time to absorb the liquid. Stir several times and add more liquid as necessary to ensure the ingredients are wet and there is a small amount of liquid in the bottom of the bowl before you place it in the casserole.
Combine saltine cracker crumbs with the bread crumbs and cereal crumbs. Add the grated Parmesan cheese and stir in seasoned salt or other favorite seasonings along with fresh black pepper.
3 cups chicken stock
1 cup white wine
1 large whole chicken breast, boned and skinned
1/2 pound mushrooms
1/2 pound curly noodles
3 tablespoons flour
1/2 cup milk
12 ounces frozen baby peas
1/2 cup saltine crackers crushed
1/4 cup seasoned Italian bread crumbs
1/4 cup crushed corn flakes
1/4 cup grated Parmesan cheese
poultry seasoning, to taste
salt and pepper, to taste