01 - Preheat oven to 400°F. Lightly grease a medium baking dish with olive oil or cooking spray.
02 - Heat 1 tbsp olive oil in a large skillet over medium-high heat. Season chicken pieces with salt, pepper, and smoked paprika. Sauté for 4–5 minutes until lightly golden on all sides but not cooked through. Transfer to a plate and set aside.
03 - In the same skillet, add remaining olive oil. Sauté sliced onion for 2 minutes until softened, then add minced garlic and cook until fragrant, about 30 seconds.
04 - Add zucchini slices and chopped sun-dried tomatoes to the skillet. Cook for 3–4 minutes, stirring occasionally, until zucchini begins to soften but still holds its shape.
05 - Stir in baby spinach and cook for 1–2 minutes until just wilted. Remove skillet from heat.
06 - In a mixing bowl, combine heavy cream, dried oregano, dried basil, chili flakes (if using), half the crumbled feta, and half the grated mozzarella. Season with salt and pepper to taste. Whisk until well blended.
07 - Arrange sautéed vegetables and seared chicken pieces evenly in the prepared baking dish. Pour cream mixture over the top, ensuring ingredients are well coated.
08 - Sprinkle remaining feta, remaining mozzarella, and all the Parmesan cheese evenly over the top of the dish.
09 - Bake for 25–30 minutes, or until chicken is cooked through (internal temperature reaches 165°F) and the cheese topping is golden brown and bubbling.
10 - Let the dish rest for 5 minutes before serving to allow flavors to meld. Garnish with fresh basil leaves and serve warm.