1. Start with the dressing by simply mixing together the liquid ingredients and the lemon thyme. Keep cool until use.
2. Cook the pasta in salted water, following the instructions on the pack until al dente and roast the walnuts until golden.
3. Cut the radicchio, chicory, fennel and apple into thin strips. Add them to the pasta and season with salt, pepper and a few tablespoons of the dressing.
4. Garnish with walnuts and the greens of the fennel. Serve immediately with some extra dressing.