Favorite Tater Tot Casserole

1 pound hamburger
2 cans cream of mushroom soup
1 1/2 soup cans milk
1 small package frozen tater tots
1/2 cup sour cream
1 cup grated cheddar cheese

Preheat oven to 425 degrees. Brown ground beef in a skillet; drain fat. In medium-sized bowl mix soup, milk, and sour cream. Add soup mixture to hamburger and stir. Pour hamburger mixture into a 13×9x2-inch baking pan. Spread tater tots in a single layer on hamburger mixture. Bake for 15 minutes. Remove from oven and sprinkle cheese over top. Return to oven for 10 minutes.