Preheat your oven to 350°F (175°C).

In a large skillet, brown the ground beef over medium heat. Drain the excess fat.

Add the diced onion to the skillet and sauté until the onion becomes translucent.

Stir in the frozen mixed vegetables, garlic powder, paprika, salt, and pepper. Cook for a few minutes until the vegetables are heated through.

In a separate bowl, combine the cream of mushroom soup and milk, mixing well.

In a greased 9x13-inch baking dish, layer half of the sliced potatoes on the bottom.

Spread the beef mixture evenly over the potatoes.

Pour the soup mixture over the beef evenly.

Top with the remaining potatoes, ensuring everything is covered.

Cover the baking dish with aluminum foil and bake for 45 minutes.

Remove the foil and sprinkle shredded cheddar cheese on top. Return to the oven and bake for an additional 15 minutes, or until the cheese is melted and bubbly and the potatoes are tender.

Let cool for a few minutes before serving.