In A Skillet Over Medium Heat, Brown The Ground Beef With Onions Until No Pink Shows On The Beef; Drain. Mix In Green Pepper And Mushrooms And Cook For A Few Minutes. Add Tomatoes With Juice, Spaghetti And Water; Stir. Add Italian Seasoning, Salt And Pepper. Cook About 15 Minutes Or Until Spaghetti Is Tender, Stirring Occasionally. Add Cheese And Stir Until Melted