Vellutata di porri (Creamy leek and potato soup)
- Peel off and discard the green outer leaves of the leeks. Slice into thin discs. Place the butter and half the oil in a large saucepan over a low heat. Once the butter has melted and the oil is hot, add the leeks and fry for 5 minutes, stirring with a wooden spoon. Add the potatoes, season with salt and pepper, sprinkle with the thyme, and stir. Pour in the stock and cook for 1 hour, stirring regularly. At the last minute, stir in the saffron.
- Take the soup off the heat and purée with a hand-held blender. If you don't have one, allow the soup to cool down, then process in a blender until it becomes a creamy purée.
- Cut the bread into dice, heat the remaining oil in a non-stick pan over a medium heat, then fry the bread until golden brown. Set aside. Reheat the vellutata and when hot serve in individual bowls topped with a little extra olive oil and the croutons.