My sister gave me this recipe and I make it fairly often. I regularly double it (it's great as a leftover).
1 Cup Chicken broth
1 Cup Half and half
2 Tbl Wine (Marsala wine; the cooking wine seems to work)
1/4 Cup Flour
1/4 Cup Butter
2 Cups Cooked chicken (one rotisseried chicken from the deli section at grocery store)
5 or 6 mushrooms, sliced and sauteed (avoid portabellos; they tend to turn the sauce gray)
Cook spaghetti according to package.
In medium saucepan, melt butter over medium heat. Add flour and pepper to taste. Cook, stirring constantly, until it turns a light brown. Combine chicken broth and half-and-half, and add all at once to butter/flour mixture. Stir constantly until thickened. Stir in chicken, spaghetti, and mushrooms. Stir in wine. Pour into casserole dish, sprinkle parmesan cheese over top, and bake in 350 degree oven for 30 minutes. Yields four or five servings.
(Note: When doubling the recipe, it has seemed a little dry. I therefore modified it by tripling the chicken broth and half-and-half, but only doubling the flour and butter. You'd think that would make the sauce a little thin, but it seems to work)