In a 12-inch cast iron skillet, cook the ground beef with diced onion, garlic powder, salt, and black pepper over medium heat until the beef is fully browned and no longer pink, about 7 to 9 minutes.
Stir in the cream cheese and heavy whipping cream, mixing well until the cream cheese melts into a creamy sauce.
Spread the drained green beans evenly on top of the beef mixture.
Sprinkle the shredded cheddar cheese over the green beans, cover the skillet, and continue cooking on medium heat for another 13 minutes until the cheese is melted and bubbly.