I love this one too!
As many avocadoes as you have to hand
some chicken stock
a clove of garlic.Greek yoghurt
Juice of a lemon
Put all these ingredients in the processor, and blitz,adding salt and pepper to taste,
Add the lemon juice ,more if you think it needs it
If you use home made stock, it will often make the soup thicker than if you used a stock cube.