Crumble the raw ground beef. Add the oatmeal, eggs, onion (optional), and lightly season with the pepper and season salt.
Mix the mixture very well in bowl. Add more oatmeal if you need to firm up the mixture.
Spray your baking dish with cooking spray and form your meat mixture into loaf shape. Lightly season top with pepper and season salt. Put into oven at 350 for one hour. My family likes to put ketchup onto the finished meat loaf, or dip into ketchup.