1 Pulse the mushrooms and lemon juice in a food processor until finely chopped.
2 Melt the butter in a large saucepan over a moderate heat and saute the shallots for 3-4 minutes, stirring occasionally. Add the mushrooms and bay leaf to the saucepan and cook for 15 minutes, stirring occasionally, until the liquid from the mushrooms has been released and then evaporated.
3 Cover with the chicken stock and bring to the boil. Reduce to a simmer and cook gently for 20 minutes.
4 Remove from the heat and puree until smooth using a stick blender. Add the cream, bring back to the boil, then keep hot over a very low heat. Adjust the seasoning if necessary.
5 Combine the chopped herbs with the olive oil for the croutons.
6 Melt the butter in an herb oil in a frying pan over a medium-high heat, then add the cubes of bread and saute, tossing occasionally, for 3-4 minutes, until golden and crispy, making sure you season them as well.
7 Ladle the hot soup into serving bowls and garnish with a few croutons. Serve immediately.