Whisk together for a minute or two. If it's too thick for your liking (depends on the salsa you use), add about half a can of water. I use the bean can and fill that halfway. But you can use as much water as you like. Just make sure to whisk well after each addition so you get a sense of the consistency before you add additional water.
Heat over medium heat, stirring most of the time to keep things from burning on the bottom of the pot.
Serve with your favorite garnish.
Video
Notes
Please note that the nutrition data given here is a ballpark figure. Exact data is not possible.