Cut the avocados in half lengthwise, remove the seeds, remove the flesh from the skins with a spoon and mash (if the avocados are still a little unripe and do not mash well, you can add a tbsp. of sour cream to the puree to make it more spreadable). Remove the stalk from the tomatoes, remove the seeds and finely dice them. Finely dice the onion and press the garlic. Remove the seeds from the chiles serranos and cut them into very small pieces (grind the dried chiles). Mix all ingredients thoroughly in a baking bowl and bring the puree to the table.
Tip: Avocado puree is a versatile dip and tastes just as good with grilled meats as it does with vegetables, cornmeal chips and tortillas.