2 tbsp. butter
1 lb. ground beef
1/4 c. sliced onions
2 (10 1/2 oz.) cans undiluted tomato soup
1 1/2 c. canned corn, drained
1-2 c. mashed potatoes
1 egg

In large skillet, melt 2 tablespoons butter. Add 1 pound ground beef and 1/4 cup chopped onions. Cook, stirring over medium heat, stirring until meat browns. Stir in undiluted tomato soup, and drained canned corn.

Put mixture in greased casserole dish. Cover with 1-2 cups mashed potatoes. Brush top with 1 egg yolk, beaten with 1 tablespoon butter. Bake at 450 degrees until top is brown, approximately 25 minutes.