01 - Preheat oven to 400°F. Lightly grease a 9x13-inch baking dish with cooking spray or a small amount of oil.
02 - Heat 1 tablespoon olive oil in a large skillet over medium heat. Add ground turkey and cook until browned and cooked through, breaking up with a spatula, about 5-6 minutes. Remove turkey from skillet and set aside on a plate.
03 - Add remaining olive oil to the same skillet. Sauté onion for 2-3 minutes until softened. Add garlic and red bell pepper, cooking for another 2 minutes until fragrant.
04 - Stir in diced sweet potatoes, thyme, oregano, smoked paprika, salt, and pepper. Cook, stirring occasionally, for 5 minutes to begin softening the potatoes.
05 - Add spinach and cooked turkey back to the skillet. Mix well and cook until spinach is just wilted, about 1-2 minutes.
06 - Transfer the mixture to the prepared baking dish. Pour chicken broth evenly over the top. Sprinkle mozzarella and Parmesan cheese evenly across the surface.
07 - Cover the baking dish with aluminum foil. Bake for 30 minutes to allow sweet potatoes to steam and tenderize.
08 - Remove foil and bake for an additional 10-15 minutes, until sweet potatoes are fork-tender and cheese is golden brown and bubbly.
09 - Let the casserole rest for 5 minutes before serving to allow it to set and make serving easier.