Begin by rinsing and chopping the green beans and potatoes into bite-sized pieces, and finely dicing the onion. Set aside.

In a large skillet, heat the pan over medium heat and add the ground beef. Cook for 8-10 minutes until browned, then add the diced onions for an additional 3-4 minutes.

In a casserole dish, mix the browned beef and softened onions with the chopped green beans, potatoes, and the can of tomato soup. Stir gently.

Sprinkle in the salt, pepper, and garlic powder, mixing thoroughly. If using cheese, add it evenly over the top.

Preheat your oven to 350°F (175°C). Cover the casserole dish with foil and place it in the oven for approximately 45 minutes, removing the foil in the last 10 minutes.

Once baked, check the potatoes for tenderness and let the casserole rest for a few minutes. Garnish with parsley or chives before serving.