Sweet Potatoes with Raisins and Poblano Chile Rajas

1. Preheat oven to 375F.
2. Peel sweet potatoes and cut into 1/2-inch thick rounds. Shingle in greased baking dish large enough to hold slices in single overlapping layer. Brush with 1/2 tablespoon melted butter. Pre-bake for 40 minutes at 375F. Meanwhile, add 1/2 tablespoon butter to skillet over medium heat; heat to foaming. Then, add raisins and sauté lightly. Remove from heat and set aside.
3. Char and peel chiles. Remove and discard stems and seeds; cut into 1/4-inch strips. Peel and cut onion into 1/4-inch slices; separate into rings. Combine chile strips and onion rings; toss with remaining 1 tablespoon melted butter.
4. After 40 minutes, remove potatoes from oven and sprinkle raisins, chiles and onions on top. Return to oven and bake for 30 minutes more.
5. To serve, sprinkle cilantro sprigs over warm potatoes and drizzle with crème fraiche. Serve immediately.

Recipe by Chef Robert Del Grande.