Place a 10-inch skillet over medium heat until warmed up and ready to go. While it's heating up, use a sharp knife to cut all of the types of cheese into small cubes.

Add all of the cubed cheeses and milk, and reduce the heat to low.

Drain the liquid from the diced tomatoes or chiles, and add to the cheeses. Add the seasonings as well.

Stir everything together well, and then adjust the thickness of your dip! Is your dip too thin? Let it simmer for a few more minutes, for moisture to evaporate. Is it too thick? Add a tablespoon of milk - or, add some of the liquid that was drained from the canned tomatoes and chiles, for an extra boost of flavor!

Dice up the avocado, and sprinkle it across the top of the dip.

Serve hot alongside a bag of tortilla chips, pita chips, or corn chips!