500 g (1 lb) chestnut mushrooms, trimmed and roughly chopped
2 tablespoons thyme leaves, plus extra to garnish
600 ml (1 pint) chicken or vegetable stock
2 tablespoons Dijon mustard plus 1 teaspoon
200 ml (7 fl oz) crème fraîche
8 thin slices of small French baguette, toasted
8 thin slices of rinded goats’ cheese
salt and pepper
Heat the oil in a large, heavy-based saucepan and cook the onion over a medium heat, stirring occasionally, for 3 minutes. Add the mushrooms and thyme leaves and cook, stirring occasionally, for 5 minutes until the mushrooms are tender and browned. Pour in the stock, add the 2 tablespoons mustard and bring to the boil. Reduce the heat and simmer for 5 minutes.
Transfer the soup to a food processor and whizz until almost smooth, then return to the pan, add the crème fraîche and season generously with a little salt and some pepper. Heat through for 1 minute.
Thinly spread the baguette slices with the remaining teaspoon of mustard and place a goats’ cheese slice on top of each. Cook under a preheated high grill for 1–2 minutes until the cheese is just beginning to brown in places.
Serve the soup ladled into warmed serving bowls with the croûtes on top, garnished with extra thyme leaves.