Melt 2 tablespoons of the butter, mix in flour and gradually blend in the chicken broth, cream, and wine.
Cook, stirring, for about 3 minutes after mixture starts to simmer.
Stir in 1/2 cup of the Parmesan cheese.
Measure out 1 cup of the sauce and blend in remaining cheese.
Melt the remaining 4 tablespoons butter in a pan, add mushrooms, and cook quickly, stirring, until lightly browned.
Bring a quantity of salted water to boiling, add noodles and cook until just tender to bite, but not soft; drain.
Combine the large portion of sauce, mushrooms (save a few slices for garnish), hot noodles, and chicken; salt to taste.
Turn into a large shallow casserole or individual casseroles.
Spoon the 1 cup of sauce evenly over the surface and top with reserved mushroom slices.
Bake in a 375° oven until bubbling; allow 15 minutes for large casserole and about 8 minutes for individual ones.
Broil tops until lightly browned.