In a large saucepan, heat the oil over medium heat and sauté the garlic, onions, and 1/4 teaspoon of salt for about 3 minutes, until the vegetables are soft. Add the cauliflower and sauté for another minute.
Add the vegetable broth, increase the heat to high, and bring just to a boil. Reduce the heat to medium and simmer for 20 to 30 minutes, until the cauliflower is completely tender.
Remove the saucepan from the heat and allow the soup to cool slightly; stir in the nuts.
Pour the soup into your blender in batches and blast on high for about 1 minute, until smooth and creamy.
Return the soup to the saucepan and warm it over low heat. Stir in salt to taste.
To serve, ladle the soup into bowls and garnish with either chopped chives or grated nutmeg.