Begin by preheating your oven to 350°F (175°C) to prepare for cooking.
In a large mixing bowl, thoroughly combine the ground beef, breadcrumbs, finely chopped onion, green bell pepper, egg, garlic powder, Worcestershire sauce, and a generous pinch of salt and pepper. Mix everything well until the ingredients are evenly distributed.
Shape the beef mixture into four evenly sized patties, about 1 inch thick, and set them aside on a plate.
Heat a large skillet over medium heat. Once hot, add the patties and brown them for approximately 3-4 minutes on each side until they develop a nice crust. Once browned, transfer the patties to a 9x13 inch baking dish.
In the same skillet used for the patties, add the cream of mushroom soup and beef broth. Stir the mixture well and bring it to a gentle simmer, allowing the flavors to meld together.
Carefully pour the creamy soup mixture evenly over the browned hamburger patties in the baking dish. Then, sprinkle the frozen mixed vegetables on top, distributing them evenly.
Layer the thinly sliced potatoes over the mixture, slightly overlapping each slice to ensure full coverage, creating a beautiful pattern.
Generously sprinkle the shredded cheddar cheese atop the potato layer for a melty, cheesy finish.
Cover the baking dish tightly with aluminum foil to trap in moisture and bake in the preheated oven for 45 minutes.
After 45 minutes, carefully remove the foil and continue baking for an additional 15-20 minutes, or until the potatoes are tender and the cheese is bubbly and lightly golden brown.
Allow the dish to cool for a few minutes before serving to let the flavors settle.
Notes
Serve warm, garnished with parsley, and pair with crusty bread or a salad.