In a blender place cucumber, avocado, spring onion, 2T of lime juice and 2T of coriander with 1 cup of iced water. Season with salt and ground pepper, then blend until smooth. Transfer to a large jug and stir in the coconut cream. Taste and adjust seasoning if necessary. Place in fridge and chill for at least 30 minutes.
In a bowl combine canola oil, sambal oelek, crab, remaining lime juice and coriander. Season with salt.
When ready to serve, divide the soup into your 8 shot glasses (or small bowls). Top with a spoonful of the spicy crab mixture and serve immediately.