Caroline Samuels creates a Mushroom Soup

1. Melt the butter in a saucepan over a gentle heat and toss in the onions. Cover and sweat until the onions are completely soft.
2. Meanwhile, chop the mushrooms up very finely and add to the pan and cook over a high heat for a few minutes. Lower the heat, sprinkle in the flour and cook for 2–3 minutes.
3. Add enough stock and milk to just cover the vegetables, stirring all the time.
4. Bring to the boil and simmer for a few minutes or for longer if you want a more concentrated mushroomy flavour… and that’s it!