Thoroughly wash the vegetables. Use a potato peeler to remove the outer filaments of the celery, scrape away the outer part of the carrots and peel the potatoes. Remove the outermost leaves of the red cabbage and thinly slice some of them. Slice the curly cabbage and the leek. Place all the vegetables in a pan and cover with water. Bring to the boil, lower the flame and cook for 50 minutes. Add salt to taste, along with some black ground pepper if you wish. Fill another pan with cold water and bring to the boil. Add a pinch of salt and cook the Arborio rice PDO for 14 minutes then drain. Pour the hot soup into the bowl, add the rice, a handful of parsley and a drizzle of oil.