Prepare and Season: Cut the chicken breasts horizontally to make 4 thin cutlets. Pat dry with paper towels. Season both sides evenly with garlic powder, Italian seasoning, salt, and black pepper.

Sear the Chicken: Heat the olive oil in a large skillet over medium-high heat. Add the chicken cutlets and sear for 4–5 minutes per side until deeply golden-brown and cooked through. Transfer to a plate, cover with foil, and set aside.

Sauté Aromatics: Reduce the skillet heat to medium. Melt the butter into the remaining pan juices. Add the minced garlic and cook for about 1 minute until fragrant, ensuring it does not burn.

Deglaze and Build Sauce: Pour in the chicken broth, using a wooden spoon to scrape up all the browned bits from the bottom of the pan. Let it simmer for 2 minutes to reduce slightly.

Add Dairy and Tomatoes: Turn the heat down to low. Stir in the heavy cream and chopped sun-dried tomatoes. Bring to a gentle simmer for 3 minutes. Gradually stir in the grated Parmesan cheese until it melts completely and thickens the sauce.

Wilt Greens: Add the fresh baby spinach and rosemary sprigs to the pan. Stir gently for 1–2 minutes until the spinach is fully wilted.

Combine and Serve: Nestle the cooked chicken cutlets and their resting juices back into the sauce. Spoon the rich cream sauce over the chicken and simmer for another 2 minutes until completely hot. Garnish with fresh rosemary and serve.