Heat oven to 350 degrees. Grease 9x13 baking dish. Cook spaghetti as directed. In large saucepan, melt butter, then stir in flour, salt, pepper, oregano, and garlic powder. Cook and stir until smooth. Slowly add in chicken broth and cream. Bring to a boil, while stirring constantly. Add in wine and mix well. Add in noodles, chicken, and mushrooms. Pour in dish and top with cheese. Bake 30 minutes.