Preheat oven to 350 degrees f.
In a large bowl, combine the beef, egg, onion, milk and oats.
Season with garlic, salt and pepper to taste and place in a lightly sprayed 5x9 inch loaf pan.
In a separate small bowl, mustard and ketchup.
Mix well and spread over the meatloaf.
Bake at 350 degrees f for 1 hour.