In a large mixing bowl, combine the ground beef, breadcrumbs, chopped onion, green bell pepper, egg, garlic powder, Worcestershire sauce, salt, and pepper. Mix well until all ingredients are integrated.
Shape the beef mixture into 4 patties and set aside.
In a large skillet over medium heat, brown the hamburger patties for about 3-4 minutes on each side, then transfer them to a 9x13 inch baking dish.
In the same skillet, add the cream of mushroom soup and beef broth, stirring well to combine and bring to a simmer.
Pour the soup mixture evenly over the patties in the baking dish, then sprinkle the frozen mixed vegetables on top.
Arrange the thinly sliced potatoes over the mixture, overlapping them slightly for even coverage.
Sprinkle shredded cheddar cheese on top of the potatoes.
Cover the baking dish with aluminum foil and bake in the preheated oven for 45 minutes.
Remove the foil and bake for an additional 15-20 minutes, or until the potatoes are tender and cheese is bubbly and slightly golden.
Let cool for a few minutes before serving.
Notes
Serve hot, garnished with fresh parsley. Pairs well with crusty bread or a side salad.