Easy Ham Hash

Ingredients

• 1 pound finely ground fully cooked ham
• 1 large onion, finely chopped
• 3 medium potatoes, peeled and cooked
• 2 tablespoons butter, melted
• 2 tablespoons grated Parmesan cheese
• 1 tablespoon prepared mustard
• 2 teaspoons Worcestershire sauce
• 1 teaspoon prepared horseradish
• 1/4 teaspoon pepper
• 1 cup shredded cheddar cheese
• 1/2 cup shredded Monterey Jack cheese