Cut the carrot, turnip and parsnip into very fine strips and cook till tender in slightly-salted water or fish stock. Trim the fish and place in a deep sauté-pan, with the onion cut up in slices, the bunch of herbs and peppercorns. Add a little salt and pour on sufficient water to cover the fish well. Bring to the boil and cook gently for about 10 min. Lift out the fish and place in a deep entreé dish, sprinkle over the shredded cooked vegetables and some finely-chopped parsley, add a little of the fish liquor and serve.