1Cook noodles as directed on package, just to al dente'. Drain and set aside.
Cube chicken, place in a medium bowl.
Mince onion and celery. Set aside.
2Spray an 8x8 casserole dish with cooking spray. (you can grease the pan lightly if you prefer.)
Preheat oven to 350 degrees.
3Melt 1 T butter in a medium saucepan, over medium-high heat. Saute' the onion and celery in the butter until soft. Add the onion and celery to the chicken. Stir to mix.
4Melt 2 T butter in a medium saucepan, over medium heat. Sprinkle with 2 T flour. Stir flour, blending to make a roux. (it should look like wet sand) Let the roux brown just for a minute or two to remove the floury taste.
5Add the chicken broth, whisking to thicken. Cook for several minutes. Then add the cold milk, again whisking to thicken. Add thyme, marjoram, savory, salt, pepper and poultry seasoning. The sauce should be the consistency of a creamed soup.
6Remove pan from heat.
Fold in the sour cream. Set aside.
7Melt 2 T butter. (I used the microwave to melt the butter.) Crush the butter crackers in a small bowl. Pour the melted butter over the crackers and mix well.
8To layer the casserole:
Start with a layer of noodles, then a layer of chicken mixture. Repeat. Pour the sauce over the layers of chicken and noodles. Top with the buttered crushed crackers.
Bake at 350 degrees for 30 minute until bubbly.