- Heat a drizzle of olive oil in a large saucepan over a medium heat.
- Add the onion and cook until softened and lightly golden.
- Stir in the mushrooms and cook for 10 minutes, until softened and beginning to colour.
- Add the Merchant Gourmet Whole Chestnuts, thyme and vegetable stock.
- Bring to a gentle simmer and cook for 15 minutes.
- Remove from the heat and allow to cool slightly.
- Blend until completely smooth using a blender or stick blender.
- Season with salt and black pepper to taste.
- Divide between bowls and finish with a drizzle of truffle oil and a little grated Parmesan, if using.