Pre-heat oven to 400°F
Put parsnips in a bowl and toss with olive oil, salt and pepper.
Spread parsnips on a large, heavy baking sheet or in a shallow baking pan.
Place in pre-heated oven and roast about 40 minutes or until tender and lightly browned.
Remove from the oven and place in a warm serving dish.
Toss with thyme; adjust seasonings and serve.