Preheat and prep the pan. Set your oven to 425°F (220°C).
Line a baking sheet with parchment for easy cleanup.
Season the sweet potatoes. Toss the cubes with 1 tablespoon olive oil, cumin, smoked paprika, chili powder, salt, and pepper. Spread in a single layer so they roast, not steam.
Roast to caramelize. Bake for 20–25 minutes, flipping once, until the edges are browned and the centers are tender. Let them cool for 5–10 minutes.
Mix the dressing. In a small bowl or jar, whisk together olive oil, lime juice, honey, garlic, cumin, salt, and pepper.
Taste and adjust acidity or salt as needed.
Combine the base. In a large bowl, add black beans, corn, bell pepper, and red onion. Toss with half of the dressing.
Add the sweet potatoes. Gently fold in the roasted sweet potatoes so they keep their shape.
Finish with herbs and avocado. Add cilantro and avocado, then drizzle in the remaining dressing. Toss gently to coat without mashing the avocado.
Serve. Enjoy warm or chilled.
Taste one last time and adjust seasoning with salt, pepper, or lime juice.