Preheat oven to 400℉; place a piece of parchment paper on a large baking sheet and lightly spray with oil; place on the middle rack of the oven for 10-15 minutes
spray oil for baking sheet
Peel parsnips and cut into strips lengthwise; cut the head of lettuce in half, keeping the core intact; cut the cabbage halves in half again, keeping the core intact; set asideIf you're including an onion, cut it into wedges and set aside
1 large green cabbage, 2 pounds parsnips, 1 large sweet yellow onion (optional)
In a large mixing bowl, combine:
2+ cups oil-olive, canola or vegetable, 5 tablespoons granulated sugar, 1 teaspoon garlic powder, 2 tablespoons caraway seeds, 1 teaspoon salt, ½ teaspoon white pepper
Place parsnips in bowl and toss to gently coat; remove and set aside; do the same thing with the onion if using an onion; add a single cabbage wedge to the oil/sugar mixture, coat and set aside; repeat until all wedges are coated
Remove hot baking sheet from oven, place parsnips and cabbage wedges in a single layer; return to middle rack of oven and cook for 20 minutes; at 20 minutes, rotate the baking sheet and turn the vegetables over; continue to cook about 20 minutes or until the vegetables begin to turn golden brown and are fork tender
Notes
When it's time to flip or remove the vegetables from the baking sheet, I used a spatula instead of tongs because the spatula kept the cabbage wedges intact. I tried using tongs and the cabbage wedges fell apart.