Preheat oven to 400°F (200°C). Toss diced sweet potatoes with olive oil, paprika, cumin, salt, and pepper. Spread on a baking sheet and roast for 20–25 minutes until tender.
In a skillet, heat black beans with a pinch of salt and ¼ tsp cumin over medium heat for 5 minutes. Mash slightly for texture.
Blend avocado, Greek yogurt, lime juice, salt, and 2 tbsp water until smooth. Adjust consistency as needed.
Warm tortillas. Layer with black beans, roasted sweet potatoes, and drizzle with sauce. Top with cilantro, red onion, or cheese (optional).
