In large skillet, melt 1 tablespoon margarine over medium-high heat. Add chicken and mushrooms. Cook and stir 4 to 5 minutes or until chicken is browned. Add 1¾ cups water and 1/3 cup milk to skillet. Bring to a boil; reduce heat to medium.

Slowly stir in pasta and seasonings. Separate pasta with a fork, if needed. Return to a boil. Boil uncovered, 4 to 5 minutes, or until pasta is tender, stirring frequently.

Remove skillet from heat. (Sauce will be thin.) Stir in sour cream and bacon. Let stand 3 to 5 minutes for sauce to thicken.