Fill a large pot with water and bring it to a boil. Add medium potatoes and cook them for 10–15 minutes until they are just fork-tender. Drain and cube them.

In a large skillet, melt a drizzle of oil over medium-high heat. Add the ground beef, seasoning with salt and pepper, and cook for about 7–10 minutes until browned. Drain excess grease.

If using fresh green beans, steam or boil them for about 5–7 minutes. If using canned, simply drain them.

In a large mixing bowl, combine sour cream, mayonnaise, dried minced onion, garlic powder, onion powder, and black pepper. Stir in shredded cheddar cheese until well blended.

Gently fold in the cooked ground beef, cubed potatoes, and prepared green beans into the creamy mixture.

Preheat your oven to 350°F (175°C). Spoon the mixture into a 9x13 inch baking pan, cover tightly with foil and bake for 45–50 minutes until bubbling.

Remove the foil during the last 10 minutes of baking to allow the top to turn golden.

Let the casserole cool for about 5-10 minutes before serving.