1. In a medium bowl, mix together corned beef hash, sour cream, pickle relish, and horseradish.
2. On bottom halves of each roll, spread about 1/4 cup mixture.
3. Place rolls over broiler set at 3 to 4 inches from heat, and broil for about 5 minutes until hot.
4. Top each roll with a slice of tomato and cheese.
5. Broil again just until cheese melts.
6. Place the top rolls and cover.
7. Serve hot Corned Beef Hash Burgers with tomato ketchup.