1. Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper.

2. Toss diced sweet potatoes with 1 tablespoon olive oil, cumin, chili powder, ½ teaspoon salt, and black pepper.

3. Spread sweet potatoes in a single layer on the baking sheet and roast for 25 minutes, flipping halfway, until tender and golden.

4. While the potatoes roast, prepare the salad ingredients: rinse the black beans and corn, and chop the red onion, bell pepper, and cilantro.

5. In a small bowl, whisk together 2 tablespoons olive oil, lime juice, remaining salt, and a pinch of cumin or chili powder.

6. In a large bowl, combine the roasted sweet potatoes, black beans, corn, red onion, and bell pepper.

7. Drizzle the dressing over the mixture and gently toss to coat.

8. Top with chopped cilantro and serve warm or chilled.