Preheat oven to 400°F (200°C) and toss diced sweet potatoes with 1 tablespoon olive oil, salt, and pepper, then spread them on a baking sheet and roast until tender and lightly browned (20-25 minutes). Lightly mash the cooked sweet potatoes in a bowl, leaving some small chunks.

While sweet potatoes roast, heat the remaining 1 tablespoon of olive oil in a large skillet over medium heat, then add chopped onion and cook for 5 minutes until softened. Stir in minced garlic, chili powder, cumin, and smoked paprika, cooking for another minute until fragrant.

Add rinsed black beans and corn to the skillet with the onion mixture and cook for 3-5 minutes to meld flavors. Remove from heat and stir in the mashed sweet potatoes, then taste and adjust seasonings.

Warm tortillas lightly in the microwave, oven, or a dry skillet to make them pliable and prevent tearing.

Pour about 1/2 cup of enchilada sauce into a 9x13 inch baking dish, then fill each tortilla with 1/3-1/2 cup of sweet potato and bean filling, sprinkle with cheese, and roll it up. Place seam-side down in the baking dish and repeat with remaining tortillas.

Pour the remaining enchilada sauce evenly over the rolled enchiladas and sprinkle generously with the remaining shredded cheese.

Bake for 20-25 minutes, or until the sauce is bubbly and the cheese is melted and lightly golden.

Let the enchiladas rest for 5 minutes before serving, and garnish with fresh cilantro, avocado, or a dollop of sour cream if desired.