In a bowl combine mayonnaise, yogurt, cheddar cheese, blue cheese dressing, eggs, salt, pepper, and flavor pack from noodles. In a separate bowl combine broccoli, mushrooms, and broken noodles then toss together wet mixture and vegetables to evenly coat. Place in an 8 by 8-inch baking dish that has been sprayed with non- stick cooking spray and cook for 45 minutes covered. Then remove cover and bake for additional 15 minutes to brown. Cool for 15 minutes before serving.