01 - Preheat oven to 400°F. Lightly grease a 9x13-inch baking dish and set aside.
02 - Heat olive oil in a large skillet over medium heat. Add diced onion, minced garlic, and diced red bell pepper. Cook for 3 to 4 minutes, stirring occasionally, until vegetables are softened and fragrant.
03 - Add ground turkey to the skillet along with ground cumin, paprika, chili powder, dried oregano, salt, and black pepper. Cook for 5 to 6 minutes, breaking up the meat with a spoon, until fully browned and no longer pink.
04 - Stir drained black beans and drained diced tomatoes into the turkey mixture. Simmer for 3 minutes to meld the flavors. Remove from heat.
05 - Spread half of the diced sweet potatoes in an even layer across the bottom of the prepared baking dish. Spoon half of the turkey and black bean mixture over the sweet potatoes, spreading gently to cover.
06 - Repeat with the remaining sweet potatoes, then top with the rest of the turkey and black bean mixture, distributing evenly.
07 - Cover the baking dish tightly with aluminum foil and bake for 25 to 30 minutes, or until the sweet potatoes are nearly fork-tender.
08 - Remove the foil and sprinkle shredded Monterey Jack or cheddar cheese evenly over the top. Bake uncovered for an additional 10 minutes until the cheese is fully melted and bubbly.
09 - Let the bake rest for 5 to 10 minutes before slicing. Garnish with fresh chopped cilantro and serve with sour cream on the side if desired.