Wash and dry the courgettes. Peel the carrots. Cut both into long, thin strips with a vegetable peeler.
Wash and halve the leeks. Separate the layers.
Cook the pasta in boiling salted water according to the pack instructions.
Meanwhile, heat the oil in a pan. Fry the carrot and courgette strips over a medium heat for 1 minute.
Add the leeks to the pan and cook briefly. Season with salt and pepper.
Add the vegetable stock, soy cream and saffron threads. Bring to the boil and simmer for 2-3 minutes over a medium heat until creamy.
Drain the pasta, and add it to the vegetables.
Mix the pasta with the vegetables and season with salt and pepper. Serve sprinkled with a little chervil.