Preheat your oven to 375°F (190°C) and lightly grease a 9×13 inch baking dish. Heat the olive oil in a large skillet over medium-high heat. Add the ground turkey along with your spices, and cook until thoroughly browned, breaking the meat apart as it cooks.

Using the same skillet to retain the seasoned juices, add the diced onions and bell peppers. Sauté until the edges begin to soften, then transfer this mixture to a bowl with the cooked turkey.

Add the cubed sweet potatoes and fresh spinach to the bowl containing the turkey and peppers. Carefully toss everything together until the spinach is evenly distributed and the potatoes are coated in the pan drippings and spices.

Transfer the combined mixture into your prepared baking dish, spreading it into an even layer. Pour the chicken broth over the top, covering the dish tightly with aluminum foil to trap moisture. Bake to tenderize the root vegetables.

Remove the dish from the oven and carefully discard the foil. Sprinkle the mozzarella cheese evenly over the top, and return the dish to the uncovered oven until the cheese is melted and lightly golden.