Melt 3 Tablespoons of the butter in a heavy skillet over medium heat. If you are using fresh mushrooms, cook them first until they are soft and lightly browned.

Next, gently sauté the onions and garlic until they are are starting to soften.

Add the pepper and celery, continuing to cook for about 5 to 10 minutes.

Heat the oil for a minutes or two, then stir in the chicken and pre-cooked mushrooms. Stir in the flour and cook it until it starts to thicken lightly.

Quickly stir in the milk and continue cooking until the sauce is just starting to thicken.

Remove from the heat and add some salt and lemon pepper to taste.

Stir in the noodles.

Pour the entire dish into a 2 quart casserole dish that has been lightly sprayed with oil.

Top with bread crumbs and dollops of butter. 

Bake at 350 degrees for about 30 minutes, or until the top is browned and it is heated all the way through.

Serve hot.