Cook pasta according to package directions; drain; set aside.
Remove brown gills from undersides of mushroom caps using a spoon, and discard gills. Chop mushrooms.
Melt butter in a large saucepan over medium heat; add mushrooms and garlic. Saute 5-6 minutes or until tender. Stir in cream and milk. Bring to a boil over medium-high heat; reduce heat, and simmer, whisking constantly, 10 minutes. Stir in cheese, pepper, and salt; stir until cheese melts and mixture thickens. Stir in parsley. Serve over hot cooked pasta.