Chicken Tetrazzini

I got this recipe from a friend of mine. It turned out great and the kids loved it!

4 large chicken breasts
6 Tbls butter
1 medium onion, chopped
4 celery stalks, chopped
5 cups chicken broth
2 cans cream of chicken soup
1/2 tsp salt
1/2 c sour cream
12 oz spaghetti
1 c parmesan cheese

In a large skillet, saute onion and celery in butter. Set aside but leave butter in skillet. Put chicken in skillet and cook til no longer pink. Season with salt and pepper. In a mixing bowl, combine chicken broth, soup, salt and sour cream. Mix together and add to skillet with cooked chicken. Add in sauteed celery and onion. Add spaghetti and bring to a boil. Simmer for 20 minutes. Add parmesan cheese while simmering. Enjoy!