Cook pasta per package directions, drain and set aside. In 10 inch skillet cook onion, mushrooms and seasoning until onion is tender. Add tomatoes and tomato sauce; cook uncovered over medium high heat for another 5 minutes. Remove from heat. Stir in the pasta, green beans and 1/2 cup of shredded monterey cheese. Season to taste with salt& pepper. Stir well to mix then pour into an 8 X 12 baking dish. Top with remaining cheese. Bake at 350 degrees for 25 minutes.