Ingredients
Preparation
Step 1
With a sharp knife peel rutabaga and cut into 1/8-inch-thick wedges. In a large saucepan of boiling salted water cook rutabaga until crisp-tender, 6 to 8 minutes, and transfer with a slotted spoon to a colander. Drain rutabaga and pat dry between paper towels.
Step 2
Peel turnips and cut into 1/8-inch-thick wedges. Cook turnips in boiling salted water until crisp-tender, 3 to 4 minutes, and transfer with slotted spoon to colander. Drain turnips and pat dry between paper towels.
Step 3
Peel parsnips and cut diagonally into 1/8-inch-thick slices. Cook parsnips in boiling salted water until crisp-tender, 3 to 4 minutes, and transfer with slotted spoon to colander. Drain parsnips and pat dry between paper towels.
Step 4
In a bowl toss together vegetables. Vegetables may be cooked 1 day ahead and chilled, covered.
Step 5
Preheat oven to 350° F. and butter a 2-quart gratin dish, about 12 by 9 by 2 inches.
Step 6
In gratin dish arrange one third vegetables and sprinkle with 1 tablespoon flour, 1/4 cup Gruyère, and salt and pepper to taste. Top cheese with half of remaining vegetables, remaining tablespoon flour, 1/4 cup cheese, and salt and pepper to taste. Arrange remaining vegetables over cheese and pour cream and milk over vegetables.
Step 7
Sprinkle remaining 3/4 cup cheese over vegetables and bake in middle of oven, covered, 30 minutes. Uncover gratin and bake until bubbling and golden, about 40 minutes more.
