Fry 1 lb of lean ground beef and onion- when done- drain.
Add 1 can of tomato soup to hamburger and mix until all meat is covered. Shut burner off.
In a Casserole dish place the hamburger with tomato soup and spread evenly.
Drain 1 can(14.5oz) of Green beans and (15.25 oz) corn and spread evenly across the top of Hamburger.
Drain potatoes and add about 1/3 cup of milk,4 tablespoons of butter, a dash of salt and pepper. Mash until the potatoes are as smooth as possible. You can add more or use less milk for the desired consistency
Add the mashed potatoes to the top of the ground beef and vegetables. and spread evenly across.
Take cheese slices and add each slice evenly and closely to each other across the top of the potatoes. You can double the amount of cheese in case You like lots of cheese.
Bake at 350 degrees covered until cheese is melted and the casserole is heated thoroughly though.