Sweet Potato Crostini with Avocado Salsa

Preheat oven to 425°F. Prick the sweet potatoes in a few places with a fork. Bake 30 to 40 minutes, until a fork inserted in a sweet potato reaches the core with some resistance. Do not cook until tender. Remove sweet potatoes from oven and cool. 2. Scoop avocado flesh into a bowl and mash it. Stir in corn and black beans. Reserve about 1 tablespoon each of the tomato, scallions, and cilantro; add the remaining tomato, scallions, and cilantro to avocado mixture. Add lemon juice, jalapeño, garlic, and salt; mix well. Taste and adjust seasoning. 3. Cut the sweet potatoes into twelve ⅓-inch-thick rounds. Toast them in a toaster oven until the edges are brown. You may need to repeat the toasting cycle once or twice. (Or arrange rounds on a parchment-lined baking sheet and bake in a 425°F oven 10 to 15 minutes or until edges are brown, turning once halfway through baking.) 4. Arrange toasted rounds on a platter. Top each round with a scoop of avocado mixture. Top with the reserved tomato, scallions, and cilantro. If desired, sprinkle lightly with chipotle powder. Serve chilled or at room temperature.