1. Adjust oven rack to middle position, place rimmed baking sheet on rack, and heat oven to 425°F. Cut celery root into 3/4-inch-thick rounds. Cut each round into 3/4-inch-thick planks about 2 1/2 inches in length.

2. Toss celery root, carrots, parsnips, and shallots with 1 teaspoon salt and with pepper to taste in large microwave-safe bowl. Cover bowl and microwave until small pieces of carrot are just pliable enough to bend, 8 to 10 minutes, stirring once halfway through microwaving. Drain vegetables well. Return vegetables to bowl, add turnips and oil, and toss to coat.

3. Working quickly, remove baking sheet from oven and carefully transfer vegetables to baking sheet; spread into even layer. Roast for 25 minutes.

4. Using thin metal spatula, stir vegetables and spread into even layer. Rotate pan and continue to roast until vegetables are golden brown and celery root is tender when pierced with tip of paring knife, 15 to 25 minutes longer. Transfer to platter, sprinkle with parsley, and serve.

Serves 6