Preheat your oven to 375°F (190°C). Grease a 9×13-inch baking dish and set aside.
In a large skillet over medium heat, cook the ground beef until browned and cooked through, about 5-7 minutes. Drain any excess fat.
Add the diced onion and minced garlic to the skillet with the ground beef. Cook until the onion is translucent and the garlic is fragrant, about 3-4 minutes.
Stir in the condensed cream of mushroom soup, ketchup, mustard, Worcestershire sauce, salt, and pepper. Mix until well combined.
Remove the skillet from heat and stir in 1 cup of shredded cheddar cheese.
Transfer the beef mixture to the prepared baking dish, spreading it out evenly.
Arrange the frozen French fries on top of the beef mixture in a single layer.
Bake in the preheated oven for 25-30 minutes, or until the fries are golden brown and crispy.
Remove the casserole from the oven and sprinkle the remaining 1 cup of shredded cheddar cheese over the top. Return to the oven for an additional 5 minutes, or until the cheese is melted and bubbly.
Garnish with chopped fresh parsley before serving.