Mushroom and thyme soup with roquefort croutons

Soak porcini in the boiling water in a bowl until softened (10-15 minutes).

Meanwhile, heat half the butter and half the oil in a large saucepan over medium-high heat until butter foams. Add leek and chopped garlic and sauté, stirring occasionally, until translucent (4-5 minutes). Stir in portabello mushrooms and half the thyme sprigs and sauté until beginning to soften (6-8 minutes), then add stock, porcini and the soaking water, and season to taste. Bring to a simmer and cook until well flavoured (10-15 minutes). Discard thyme, add crème fraîche and purée with a stick blender (or in batches in a food processor) until smooth. Stir in half the lemon rind and keep warm.

Preheat grill to high and toast baguette slices, turning once, until golden brown (2-3 minutes).

Heat remaining butter and remaining oil in a large frying pan over high heat. Add other mushrooms, cap down, then add the bruised garlic. Season to taste and fry until golden brown (2-3 minutes). Turn mushrooms, add remaining thyme and cook for another minute. Remove from heat, add vinegar and lemon juice.

Ladle soup into warm serving bowls and top with fried mushrooms and garlic and buttery pan juices. Scatter with extra thyme and lemon rind, and serve hot with croutons spread with roquefort.