1-Bring plenty of salted water to the boil in a saucepan and cook the pasta until it is “al dente”; drain the pasta and spread it on top of a baking tray brushed with oil, stir the pasta and leave to cool completely. Mix the lemon juice with a pinch of salt and pepper in a bowl, add the remaining extra virgin olive oil and beat the ingredients gently together.
2- Wash the fillets of dentex, dry them and with a sharp knife, crosscut them into very thin slices, place them on a serving dish brushed with a little of the previously prepared sauce, drizzle half of the oil and lemon sauce over the fillets; leave the dentex to marinate in the fridge for about 15 minutes.
3- In the meantime, prepare the fennel by removing the tough leaves and the stalks, wash and cut into very thin slices and soak in cold water.
4- Blanch the tomatoes in boiling water, drain, remove the skin, seeds and juice and cut the pulp into pieces; place the pieces in a bowl, add the slices of drained fennel, the cold pasta, dress with the oil and lemon sauce, stir and place the slices of marinated dentex over the top. Serve the penne salad sprinkled with washed and roughly chopped chives and the peel of an orange cut into thin strips and blanched for a few minutes in boiling water.