Step 1 Heat the oven to 375 degrees. Leave the small parsnips whole, and cut the larger ones in half, so they will be uniform in size and cook evenly.
Step 2 On a shallow baking tray, toss the parsnips with the thyme, marjoram, olive oil, three-eighths teaspoon salt and white pepper to taste. Place the tray in the oven and roast until parsnips are tender, about 45 minutes.