01 -
Preheat oven to 350°F (175°C).
02 -
In a large bowl, mix ground beef, chopped onion, garlic powder, salt, black pepper, breadcrumbs, and beaten egg until fully incorporated.
03 -
Form the mixture into four oval-shaped patties and set aside.
04 -
In a skillet over medium heat, brown patties approximately 4 minutes per side without fully cooking.
05 -
Whisk together beef broth and cream of mushroom soup in a separate bowl until smooth.
06 -
Grease a 9x13-inch baking dish. Pour half of the soup mixture evenly across the bottom.
07 -
Place browned patties on soup layer. Pour remaining soup mixture over patties and evenly distribute frozen mixed vegetables on top.
08 -
Spread prepared mashed potatoes evenly over vegetable layer and gently pat down.
09 -
Sprinkle shredded cheddar cheese evenly over the mashed potatoes.
10 -
Cover baking dish with aluminum foil and bake for 30 minutes in preheated oven.
11 -
Remove foil and continue baking an additional 15 to 20 minutes until cheese is melted and bubbly.
12 -
Allow to cool for several minutes before slicing and serving.