In a seperate bowl mix the cream of mushroom soup with half a can of milk.
Add the beef to the soup and add water chestnuts if you like them (warning most kids hate them) and mix well.
Pour this mixture in the bottom of a casserole dish.
Cover the top of the meat mixture with half the cheese.
Top it with tator tots and bake until the tator tots are crisp, sprinkle the remaining cheese on top and let it melt. It doesn't get any easier than that!!! My kids hate water chestnuts so I don't use them, and my kids claim they hate mushrooms but they don't taste the mushrooms in the soup. It's a winner!!