In a large soup pot, heat butter and oil. Add garlic and onion and saute until softened.
Add carrots, cauliflower and sherry; heat and stir together for 3 minutes. Add chicken stock. Bring to a boil, reduce heat, cover and simmer 30 to 35 minutes or until vegetablles are tender.
Add parsley. Puree in a blender or food processor.
Return mixture to saucepan. Add milk and nutmeg, salt and pepper to taste. Heat, stirring, until very hot, but do not allow to boil.
Squeeze over lime juice, and garnish with chives before serving.