1.Preheat oven to very hot, 220C. Line an oven tray with baking paper.
2.In a large saucepan, heat butter on medium. Saute mushrooms 4-5 minutes until tender.
3.Reserve ½ cup mushrooms, Add leek and garlic to remaining in pan. Saute 3-4 minutes until leek is tender.
4.Pour stock into pan with potato. Bring to boil. Reduce heat to low and simmer, partially covered, 8-10 minutes until potato is tender. Puree using a hand blender until smooth.
5.Return soup to clean saucepan. Stir in cream and season to taste. Stir over a low heat until soup is hot. Serve topped with reserved mushrooms and chives. Accompany with chargrilled bread.
If preferred, use milk in place of cream and finish soup with a swirl of cream.Note