Preheat the oven to 375°F (190°C). Lightly oil a 9x9-inch baking dish.

Peel and cube the sweet potatoes into roughly 1-inch pieces. Toss them with half the olive oil, a pinch of salt, and black pepper.

Spread the sweet potatoes on a baking sheet and roast for 15 to 20 minutes until tender and slightly browned. Alternatively, sauté the cubes in a skillet with a splash of oil over medium heat for 12 to 15 minutes, stirring until fork-tender.

While the potatoes cook, heat the remaining tablespoon of olive oil in a large skillet over medium heat. Add the chopped onion and cook until translucent, about 4 minutes.

Add the minced garlic and diced red pepper to the skillet. Sauté for 2 minutes until fragrant and slightly softened.

Add the ground turkey to the skillet. Break it up with a spoon and cook until no pink remains, about 6 to 8 minutes. Season with smoked paprika, cumin if using, dried thyme, salt, and pepper. Stir well and taste; adjust seasoning.

Combine the roasted or sautéed sweet potatoes with the turkey mixture in the prepared baking dish. Spread evenly.

Sprinkle the shredded mozzarella or cheddar over the top.

Bake the dish for 10 to 15 minutes, or until the cheese is fully melted and the bake is heated through.

Let the casserole rest for 5 minutes before slicing. Sprinkle with chopped parsley or cilantro if using and serve warm.