250g fresh chestnuts, scored. Chestnuts are available from most supermarkets or fruit & veg shops during winter, if you cannot find any replace with potatoes (peeled & diced).
40g unsalted butter
1 large brown onion, peeled and chopped
2 cloves garlic, peeled and chopped
1 tsp thyme leaves
300g field mushrooms, chopped
200g mushrooms, chopped
25g dried sliced mushrooms (soaked in 500ml water)
1 litre vegetable stock
1/3 cup dry sherry (or white wine)
sea salt and freshly ground black pepper
200ml crème fraiche
Preheat oven to 200°C (180°C fan-forced) and 2 line a baking tray with baking paper.
Place chestnuts in a medium saucepan covered in cold water, over a medium heat. Bring to the boil, cook for 15 minutes or until flesh is tender. Drain, wrap in a tea towel and allow to cool down for 5 minutes. Whilst still warm, peel the outer shell and the inner membrane. Place peeled chestnuts in a bowl and set aside for later.
Melt butter in a large saucepan over a medium-low heat. Add onion, garlic thyme, and mushrooms, cook, covered for 15 minutes or until onion is soft.
Add mushrooms and Soaking liquid to onion mixture with chestnuts, stock, sherry, sea salt and pepper. Bring back to the boil and gently cook for a further 15 minutes.
Meanwhile, place thawed pastry sheet on a lightly floured surface and roll to a thickness of 3mm. Place a serving bowl upside down and using it as a guide cut six pastry rounds. Invert (inverting the pastry will give you a more even rise) pastry rounds onto prepared baking trays and bake in preheated oven for 20 to 25 minutes or until golden brown.
Using a blender, puree the mushroom mixture until smooth. Add crème fraiche and puree until combined. Check seasoning and adjust accordingly.
To serve, evenly divide soup between the bowls and top each with a pastry lid.