Start by grating the aged cheddar and American cheeses into large shreds using the larger hole on a box grater.
Add the ingredients minor 1/2 cup of milk in a medium saucepan.
Cook the mixture over low heat and continue stirring it occasionally until the cheese completely melts.
When the mix starts to thicken, add 1/2 cup of milk to reach the desired creaminess.
Continue whisking and stirring the mix until it thickens to the desired consistency.
Take off the heat and let the melted Velveeta cheese cool down for a few minutes, then serve immediately with your favorite snack!