Bring A Large Pot Of Lightly Salted Water To A Boil. Add 1 Tablespoon Oil To The Water To Prevent Sticking. Add Pasta And Cook For 8 To 10 Minutes Or Until Al Dente; Drain. Preheat Oven To 350 Degrees F (175 Degrees C). In A 2 Quart Saucepan Over Medium Heat, Combine The Cream Of Mushroom Soup, Mixed Vegetables, Canned Tuna, And 1 Cup Of The Cheddar Cheese. Gently Fold Pasta Into The Soup Mixture And Mix Thoroughly. Pour Pasta And Soup Mixture Into A 11X7 Inch Baking Dish. Sprinkle Remaining Cup Of Cheese On Top. Bake In A Preheated Oven Until Cheese Is Melted And Bubbly.