Begin by chopping up the onions, or scallions, jalapeño pepper, cilantro and tomato (optional).
Warning: Caution! When chopping the jalapeño I recommend you use latex gloves or wash your hands immediately afterward. Avoid rubbing your eyes.
Next, cut the avocados in half, remove the pits, and scoop the flesh into a large bowl. Immediately add lime juice to it. This will prevent the avocados from turning brown.
Mix it up with a spoon. Take half of an avocado out, dice it with a knife and set aside.
Mash the remaining avocados with a fork to desired consistency. Add salt and mix.
Add onion, half teaspoon of jalapeño, cilantro, and tomato. Combine everything together and add remaining diced avocado to the mixture. Gently fold ingredients together. Taste. Add more jalapeño, or salt to taste.
Enjoy!