01 - Preheat the oven to 400°F.
02 - In a large skillet, heat olive oil over medium heat. Add onion, garlic, and bell pepper. Cook for 3 to 4 minutes until softened.
03 - Add ground turkey, cumin, paprika, chili powder, oregano, salt, and pepper. Cook, breaking up the meat, until no longer pink, about 5 to 6 minutes.
04 - Stir in drained black beans and diced tomatoes. Simmer for 3 minutes, then remove from heat.
05 - Layer half of the sweet potato cubes in a lightly greased 9x13-inch baking dish. Spread half of the turkey and black bean mixture evenly on top.
06 - Repeat with remaining sweet potatoes and turkey mixture to form the second layer.
07 - Cover with foil and bake for 25 to 30 minutes until sweet potatoes are nearly tender.
08 - Remove foil, sprinkle shredded cheese over the top, and bake uncovered for 10 minutes until melted and bubbly.
09 - Let rest for 5 to 10 minutes. Garnish with fresh cilantro and serve with sour cream if desired.