In a large skillet, heat the olive oil over medium heat. Add the chopped onion and bell pepper, cooking until softened, about 3-4 minutes.
Add the minced garlic and cook for an additional 1 minute, stirring frequently to avoid burning.
Increase the heat to medium-high and add the ground turkey. Cook until browned and fully cooked, breaking it apart with a spatula, about 5-7 minutes.
Stir in the diced zucchini, Italian seasoning, paprika, salt, and pepper. Cook for another 5-6 minutes, until the zucchini is tender.
Add the diced tomatoes to the skillet and stir to combine. Let it simmer for 2-3 minutes.
If using, sprinkle the shredded mozzarella cheese on top and cover the skillet. Allow the cheese to melt for about 2 minutes before serving.