Preheat your oven to 375°F (190°C).
In a skillet, cook the ground beef and onion over medium heat until the meat is browned. Drain excess fat.
Stir in the condensed cheddar cheese soup and milk. Mix until well combined.
Transfer the beef mixture to a greased 9x13-inch baking dish. Spread evenly.
Arrange the frozen French fries on top of the beef mixture.
Bake in the preheated oven for 25-30 minutes, or until the fries are golden brown and crisp.
Sprinkle the shredded cheddar cheese over the fries and return to the oven for an additional 5 minutes, or until the cheese is melted.
Remove from the oven and let cool for a few minutes before serving.