Heat up a medium to large soup pot over medium heat. When hot, add oil and let it heat up but don't let it smoke.
Add onion and saute for 2 -3 minutes. Add garlic and continue cooking for 1 - 2 minutes until it starts to brown and becomes fragrant.
Add the mushrooms plus the nutmeg and cook for 4 - 5 minutes until the mushrooms release their liquids and start to soften.
Add the salt and then the stock, bring to a boil, reduce heat and simmer for 30 minutes. The mushrooms should now be soft.
Add the coconut milk and cook for an additional 5 - 10 minutes.
Using an immersion blender, puree the mushrooms and the rest of the ingredients right in the pot. If you don't have an immersion blender, use a blender or food processor. Using an immersion blender just makes the job a little easier and less cleanup.
Taste, adjust seasoning with white pepper and salt to taste.