Cook and drain fettuccine as directed on package. Meanwhile, in 12-inch nonstick skillet, heat oil over medium-high heat. Cook mushrooms, onion, thyme, salt and pepper in oil 10 minutes, stirring occasionally, until tender. Remove from heat. Stir in flour; gradually stir in broth. Heat to boiling; boil 1 minute. Remove from heat; stir in whipping cream.