Preheat your oven to 375°F (190°C) and lightly grease a 9x13-inch baking dish.
In a large bowl, season the ground beef with garlic powder, onion powder, salt, and pepper. Mix well and form the beef into 6 patties.
Heat a skillet over medium heat and brown the patties on both sides. They don’t need to cook all the way through at this stage. Set aside.
In the same skillet, whisk 1 cup of milk with the flour until smooth. Gradually add the remaining 1 cup of milk while stirring continuously, creating a smooth gravy. Season with additional salt and pepper to taste.
Layer half of the sliced potatoes at the bottom of the prepared baking dish. Add half of the sliced onions on top of the potatoes.
Place the browned hamburger patties over the onions, then cover them with the remaining potatoes and onions.
Pour the prepared gravy evenly over the entire dish, making sure it reaches all the layers.
Cover the baking dish with aluminum foil and bake for 1 hour.
After 1 hour, remove the foil, sprinkle the shredded cheddar cheese over the top, and bake uncovered for an additional 15 minutes, or until the cheese is melted, bubbly, and lightly golden.
Let the dish rest for a few minutes before serving so the layers settle and the flavors meld together.
Enjoy!
