Cut the avocado in half, remove the pit, and scoop out the flesh with a spoon.
Place the avocado flesh in a bowl and mash it with a fork.
Finely chop the tomato, onion, cilantro, and green chili.
Add the chopped tomato, onion, cilantro, and green chili to the avocado.
Add lime juice and salt, and mix everything well.
Season with pepper to taste, if desired.