Remove the avocado flesh from the fruit, by cutting it in halves. Remove the pit and use a spoon to easily remove the flesh. Place in a bowl
Dice the onion and dice the peeled tomato
Shred the cheese
Mix all together with a fork and mesh it by hand in the bowl
The mixture should have some consistency and not be too juicy or liquid. More tomato makes it more liquid, more cheese makes it more firmAdd salt and pepper to taste. Usually the cheese will also bring salt to the dish. Serve within 30 minutes