Add the onion and saute until golden, about 5 minutes. Decrease the heat to medium, add the mushrooms, and saute for5 minutes or until soft.
Remove the mixture from the pan and set aside.
Melt 2 tablespoons of the butter in the skillet over medium heat, and add the flour, stirring constantly until the butter startsto brown and smell nutty. Be Careful not to burn it.
Add the chicken broth, the tyme, and the savory, and scrape up any flavorful brown bits in the pan.
Add milk, the cream cheese, and the cream, and whisk until smooth.
Decrease the heat to low, and simmer for 10 minutes
Add onion-mushroom mix to the pan, add the peas, cheese, Salmon, and old bay seasoning and stir.
Season to taste with salt and pepper.
Simmer until heated through and creamy, about 5 minutes.
Toss the sauce with the noodles until well coated
Pour into prepared casserole dish
Melt the remaining 2 tablespoons of butter in small pan.
Toss with bread crumbs, and sprinkle over the top of the casserole.
The casserole dish uncovered into the oven for 20 minutes, or until the bread crumbs are golden.