Cut the avocado in half lengthwise, remove the pit, peel, and dice into 1cm cubes. Reserve 4 slices for topping.

Thinly slice the onion.

Heat butter in a pot over low heat. Once half melted, add onion and sauté over medium-low heat for 2 minutes until softened.

Add water, salt, and consomme. Bring to a boil, cover, and simmer on low heat for 5 minutes. Let cool slightly.

Blend the soup and avocado in a blender until smooth. Transfer back to the cleaned pot.

Add soy milk and heat gently over low heat until just before boiling.