Guacamole should be pure and simple and mostly just mooshed up avocados. It should never contain mayo or sour cream or any ingredient such as that. If it does, you can't call it guacamole. You could call it "avocado dip" or something like that, but not guacamole. In the Notes section is a list of extras that you can add to your guac and not embarrass your friends in Texas or New Mexico!
The nutrition facts for basic guacamole are at Calorie Count!
3 Hass Avocados
1 lime (even this is optional)
a pinch of garlic powder
a pinch of salt (a great sub here is celery salt)
Get a sharp knife and a spoon and a paper towel. Slice the avocados in half and pull apart so that the seed is on one side. Use the spoon to scoop out the seed and discard. Use the same spoon to scoop the avocado out of the shells and into a medium sized bowl.
Sprinkle with the garlic and salt (or celery salt) and mix.
That's all that's necessary, but there are some great traditional ingredients as well!
Once the basic guacamole is made, you can add finely chopped jalapenos, Poblano or Serrano peppers, finely diced tomatoes, or a small bit of chopped onion. I usually add the peppers and tomatoes but rarely add onion. I do not ever pour in salsa because all that does is ruin the pretty bright green color that is the lovely avocado.
Mrs. Hass of Hass Avocado fame uses lemon juice instead of lime in her guacamole, so try that sometime and see if you like it better!
If you just gotta have avocado dip instead of guacamole, check out this recipe for Avocado Roasted Tomatillo Soup. All you have to do is eliminate the veggie stock and you have awesome green dip!