Preparation:
Melt butter in a large saucepan. Add onions and garlitablespoon Cook until tender but do not brown. Add potatoes and combine well. Stir in chicken stock and thyme. Bring to a boil. Reduce heat. Cook gently, covered, 20 minutes, until potatoes are tender.

Puree half the soup. Return to saucepan. Stir in milk and heat just until mixture comes to a boil. Stir in cheese. Cook gently, stirring, until cheese melts. Add salt and pepper to taste. Garnish each serving with chopped parsley.