Preheat oven to 350°F.

In a large skillet set over medium heat, cook the ground beef for approximately 5 minutes or until browned throughout. Stir in the taco seasoning and water, allowing the mixture to simmer gently until the liquid is fully absorbed.

Spread a generous layer of chili cheese Fritos across the bottom of a baking dish, then spoon the seasoned beef evenly over the chips. In a separate saucepan over low heat, warm the cheddar cheese soup and milk together, stirring occasionally until smooth, then pour the sauce over the meat layer.

Scatter the shredded mozzarella cheese across the top and transfer the dish to the oven. Bake for 10 to 15 minutes, or until the cheese is fully melted and bubbling.