Spiced Sweet Potato Gratin

• 4 pounds red-skinned sweet potatoes (yams; about 3 1/4 pounds)
• 1 tablespoon curry powder
• 1 tablespoon ground cumin
• 3/4 teaspoon ground cinnamon
• 3/4 teaspoon ground ginger
• 1/2 teaspoon (scant) salt
• 1 1/2 cups sour cream, divided
• 3 cups shredded extra-sharp white cheddar (about 12 ounces)

1. Preheat oven to 350F.
2. Cook sweet potatoes in large pot of boiling salted water until just tender, about 20 minutes (do not overcook).
3. Drain well and cool.
4. Peel sweet potatoes; cut into 1/4-inch-thick slices.
5. Mix curry powder, cumin, cinnamon, ginger, and salt in small bowl to blend.
6. Completely line bottom of 9-inch-diameter springform pan with sweet potato slices, filling in any spaces with cut-up sweet potato slices.
7. Press down lightly.
8. Spread 1/2 cup sour cream over sweet potatoes.
9. Sprinkle 1 tablespoon spice mixture over sour cream.
10. Sprinkle with 1 cup cheese.
11. Repeat twice with remaining sweet potatoes, sour cream, spice mixture, and cheese.
12. Place pan on rimmed baking sheet; bake until cheese is melted and sweet potatoes are heated through, about 40 minutes.
13. DO AHEAD Can be made 8 hours ahead.
14. Cover and chill.
15. If desired, reheat in 400F oven until hot, about 15 minutes.
16. Remove pan sides from gratin; cut into wedges.
17. Serve gratin warm or at room temperature.

potatoes, curry powder, ground cumin, ground cinnamon, ground ginger, salt, sour cream, white cheddar

Taken from www.epicurious.com/recipes/food/views/spiced-sweet-potato-gratin-236482 (may not work)