Remove the core and peel the pear.
Remove the stone and peel the skin off the avocado.
Cut both into small chunks. Place the pear chunks in the saucepan with the hot water and slowly bring to a simmer.
Continue simmering until the fruit breaks up easily with your fork or spoon.
Be careful not to overheat or boil too much otherwise you will lose vital nutrition from the fruit.
Take off the heat and allow to cool, then combine with the avocado pieces and carefully mash with a fork or use a blender.
Fill up your ice cube tray evenly with the purée and, when cooled completely, place in the freezer.