Preheat the oven to 350 Degrees F. Brown the ground beef in a large skillet over medium-high heat. Stir in the taco seasoning and water and cook until the mixture has thickened.
In a small saucepan combine the cheddar cheese soup and milk. Cook over medium heat while stirring until well combined and heated through.
Lightly grease the bottom of a 9 x 9-inch baking dish. Place a layer of Fritos onto the bottom of the baking dish.
Place the taco meat on top of the Fritos. Pour the prepared cheddar cheese soup over the taco meat. Top with an additional layer of Fritos. Top with shredded Mexican cheese blend.
Place into the oven and bake at 350 Degrees F. for 10-15 minutes or until bubbly. Remove from the oven and top with lettuce and tomato.