Prepartion

1. Melt butter in a saucepan over a medium heat. Add onion and mushrooms. Cook, all the while stirring, for 5 minutes. 
2. Add chicken stock. Simmer for 20 minutes. Cool slightly.
3. Scoop out 2 tbsp of mushroom. Blend the remaining mixture in a blender for 10 seconds. 
4. Return to a clean saucepan. Blend corn flour with a little milk to make a paste. Stir into the soup. Stir in remaining milk. Cook, constantly stirring, until soup thickens. Sit in cream. 
5. Put back in the 2 tbsp of mushroom taken out earlier. Heat for 3-4 minutes or until hot.