Root Vegetable Gratin

Directions

1. 1.

   Put oven rack in upper third of oven and preheat oven to 400°F.

2. 2.

   Peel parsnips and cut crosswise into 3-inch lengths with a knife, then cut lengthwise around core into 1/8-inch-thick slices with slicer (discard core). Transfer to a large bowl.

3. 3.

   Peel celery root and all potatoes (prepare russet potatoes last to avoid discoloration) and halve lengthwise, then cut crosswise into 1/8-inch-thick slices with slicer. Add to parsnips along with salt, garlic, pepper, nutmeg, broth, and 1 3/4 cups cream, tossing to combine. Transfer to gratin dish, spreading evenly.

4. 4.

   Cut out a piece of parchment or wax paper to fit just inside gratin dish, then butter 1 side of parchment. Cover vegetables directly with parchment, buttered side down, then put dish in a shallow baking pan (to catch any drips). Bake until gratin is bubbling all over and vegetables are tender when pierced with a knife, about 50 minutes. Discard parchment.

5. 5.

   Just before serving, preheat broiler. Drizzle top of gratin with remaining 2 tablespoons cream and broil 4 to 6 inches from heat until browned, 2 to 3 minutes.