01 -
Set oven to 375°F (190°C) and allow it to fully preheat.
02 -
In a large bowl, thoroughly combine ground beef, onion, garlic, breadcrumbs, milk, egg, Worcestershire sauce, salt, and black pepper. Evenly press the mixture into the bottom of a greased baking dish.
03 -
Spread ketchup evenly over the top of the meat mixture.
04 -
Place baking dish in the oven and bake for 25 minutes.
05 -
While the meatloaf bakes, add sliced potatoes to a large pot of boiling salted water. Cook until tender, about 15 minutes. Drain well.
06 -
Mash the drained potatoes with sour cream, milk, and butter until smooth. Season with salt and pepper to taste.
07 -
Carefully spread the mashed potatoes over the partially cooked meatloaf base.
08 -
Sprinkle shredded cheddar cheese and chopped green onions evenly over the mashed potatoes.
09 -
Return dish to the oven and bake for an additional 20 minutes until cheese is melted and casserole is bubbly.
10 -
Remove from oven and let rest at room temperature for 10 minutes prior to slicing and serving.