Start by preheating your oven to 375°F (190°C). Lightly grease your baking dish or skillet. Season the chicken breasts on both sides with salt and black pepper to build flavor from the start.
Heat olive oil in a skillet over medium heat. Sear the chicken for about 2–3 minutes per side until lightly golden. This step locks in juices and adds a deeper taste, even though the chicken finishes cooking in the oven.
In the same skillet, add minced garlic and cook briefly until fragrant. Stir in chicken broth, heavy cream, Italian seasoning, and red pepper flakes, letting the mixture gently simmer for a couple of minutes.
Mix in the chopped sun-dried tomatoes and freshly grated Parmesan. Stir until the cheese melts smoothly into the sauce, creating a thick and creamy texture that coats the spoon nicely.
Add fresh spinach to the sauce and stir until it wilts. This only takes a minute, and the spinach adds color and a mild earthy flavor that balances the richness.
Place the chicken back into the skillet or baking dish, spooning sauce over each piece. Transfer to the oven and bake for about 20–25 minutes, until the chicken is fully cooked and tender.
Once baked, remove the dish from the oven and let it rest for a few minutes. Garnish with fresh basil just before serving to brighten up the flavors.