Grate cheeses and mix with the corn starch. If using a pre-grated cheese, reduce cornstarch to half.
Put cheese and cornstarch mix, evaporated milk, chopped jalapeno, hot sauce/cayenne, and seasonings in a heavy bottom sauce pan.
Heat over medium heat.
Whisk cheese mixture while heating, it will slowly loosen up, and stop clumping, and eventually, it will be pourable. Approximately 10 minutes of stir time.
Taste, add salt, and adjust seasonings to your preference
Remove from heat, and pour onto chips, or into a bowl for dipping
Notes
A thin skin will set up on top of the cheese, just stir it occasionally. If making ahead of time, just reheat before serving, either in a pan on the stove top or in the microwave.