Growing up, avocado is always served and eaten as a sweet. This is something that most people in Southeast Asia would agree to. I remember having chilled avocado as a snack or dessert just scooped and mashed, served with milk and sugar or sometimes condensed milk.
That is why it took me sometime to finally eat avocado in a savory form such as guacamole, a sandwich filling or an addition to salads. Making a shake out of avocado is nothing unusual in the part of the world where I grew up. Though this may not be the case for the unexposed. My kids having lived in North America most of their life were initially turned off by the thought eating sweetened avocado. After a little coaxing they did try and learn to love it.
So this is how I make avocado shake. Take a ripe a avocado, cut in half and remove pit. Peel the skin and cut the avocado into cubes. Throw your avocado into a blender with a handful of ice, milk (amount depends on the consistency you want) sugar or condensed milk again how much depends on the level of sweetness you want. I wanted a thick consistency so I just put 2-3 splashes of miik and about 4 Tbsp of sugar. Blend until smooth. Pour into a tall glass and serve.
If you have some leftover, you can make ice pops with it. This is how it turned out when I made some a while back.