Cover the blender or food processor. The fruit should be pureed using the puree setting until it becomes a smooth paste. If you don't have a blender or food processor, you can also mash by hand or with a potato masher. Transfer the pureed avocado to a medium size pot.

Cook the pureed avocados over medium heat stirring every three to five minutes to ensure that it doesn't stick or burn. It will start to boil and rise. Keep cooking until the colour changes from pale green to a dark green or brown.

Remove the pot from the stove after the water has evaporated. Transfer the avocado mixture to a large glass bowl. Cover the bowl with cheesecloth. Then use cotton cooking twine or a rubber band to tie the cloth in place. While gripping either side of the bowl flip it over. Once upside down carefully remove the twine or rubber band and pull together the top of the cloth to make what appears like a sack.

Squeeze the mixture over a medium size basin to catch the strained oil. Keep straining until no more oil can be expressed.

Pour oil into a flip-top bottle or airtight container and store for later use.