Add butter to a saucepan and brown the ground beef you're planning to use over medium-high heat. Allowing the beef to brown will add significant flavor to this tex mex dinner later on. Drain the beef's grease accordingly.

Add in taco seasoning and water once the beef has been browned and the grease has been drained or soaked up with the use of a paper towel.

Simmer on low to allow the taco seasoning to become absorbed into the meat. Carefully watch as this action takes place so you know when it's time to move forward.

Layer your Fritos in the bottom of an 8x8 baking dish. This will become the base of your taco bake or walking taco casserole.

Top the Fritos (bottom layer) with the meat you've cooked and seasoned.

In another saucepan, add the milk and cheddar cheese and simmer over low heat. Avoid cooking this on high heat, as the milk and cheese may not blend well together.

Pour the soup mixture over the meat once it is blended and warmed.

Sprinkle the mozzarella cheese on top of the mixture. You can use your preferred cheeses during this stage.

Place into your oven at 350 degrees Fahrenheit for 12-14 minutes, or until warmed through and until the cheese has melted.

Remove from your oven and allow your casserole to cool. Serve and enjoy!