Directions:
Sprinkle the mushrooms with the lemon juice. Melt the butter in a large pan. Add the onion and garlic and cook gently for a few minutes until softened but not coloured. Increase the heat, add the mushrooms and cook for 1-2 minutes, stirring. Stir in the flour and cook for another minute, stirring.
Gradually pour the stock into the pan, add the nutmeg, season to taste and bring to the boil. Turn down the heat, cover and simmer gently for about 10 minutes or until the mushrooms are completely tender. Blend to a purée in a food processor or with a hand held blender. Return to a clean pan, season to taste and stir in most of the cream, reserving a little to garnish.
Meanwhile, make the garlic croutons. Heat the butter in a non-stick frying pan and once it has melted and is starting to sizzle, stir in the garlic and then tip in the sourdough bread cubes, tossing to coat. Season to taste and continue to sauté for 3-4 minutes until golden brown. Tip on to kitchen paper to drain off any excess butter.
To serve, reheat the soup gently, then ladle into warmed bowls and add swirls of the reserved cream. Garnish with the crunchy garlic croutons and add a sprinkling of chives to each one.