Heat a medium saucepan on a medium heat. Add a good few tablespoons olive oil and the sliced leeks. Cook covered, stirring now and then for about 10 minutes or until leeks are soft but not browned. If they start to brown, add a splash of water and turn the heat down a little.
Add sliced mushrooms and stock and bring to the boil. Simmer rapidly with the lid off until the mushrooms are tender. About 15 minutes.
Return the pan to a medium high heat. Squeeze spinach dry and add to the pot with the cream. Stir well and allow to warm back to a simmer. Taste and season with salt and pepper as needed.
To serve divide hot soup between two bowls. Drizzle over a little extra virgin olive oil and a little swirl of cream. Finish with the nuts.