The fillings for your meatloaf fall under some basic categories: (day old) crusty bread soaked in milk, ground meat, diced veggies, egg, spices.
Soak your bread that you rip or dice into cubes. This adds some texture and airiness in the loaf so it isn't completely dense with meat.
Next saute your veggies. This time I had onions, carrots, and garlic to work with. You don't need to get them completely soft because you will be baking them in the loaf for an hour and the juices from the meat will soften them.
Now combine your ground meat, 3/4 of the sauteed veggies, soaked bread, one egg, and sauces/spices in a bowl. It looks pretty gross. For my seasoning this time I went with some soy sauce, salt/pepper, and thyme.
With the remaining sauteed veggies, I mixed them with some soy sauce and some ketchup in the skillet. I then filled a loaf pan with the meaty mixture and spread the ketchup on top. Add as much or as little of this as you'd like.
I popped this bad boy in the oven for an hour at 350 degrees. You can serve with additional ketchup if your diners so desire, or perhaps ditch the ketchup alltogether and go for a gravy instead. I served with mashed potatoes for a nice hearty meat and potato comfort food dinner.