1 Make the mushroom steaks
Heat butter in a pan until lightly browned. Add the whole mushrooms and sauté until well caramelised. Set aside.
2 Cook the soup base
In a pot, add chopped mushrooms, onion, garlic, and enough water or stock to just cover. Simmer for 15 minutes.
3 Blend
Blend the mixture until smooth. Strain if you prefer a silkier texture.
4 Finish the soup
Return to heat and add milk, salt, pepper, and nutmeg. Cook for another 5–7 minutes, stirring gently.
5 Serve