Season the chicken: Pat chicken dry. Sprinkle both sides with 1/2 teaspoon salt, pepper, Italian seasoning, and paprika.
Sear for flavor: Heat olive oil in a large skillet over medium-high.
Sear chicken 4–5 minutes per side, until golden and almost cooked through. Transfer to a plate; tent with foil.
Sauté the aromatics: Reduce heat to medium. Add butter.
Stir in garlic and sun-dried tomatoes. Cook 30–60 seconds, just until fragrant.
Deglaze the pan: Pour in chicken broth. Scrape up browned bits with a wooden spoon.
Simmer 2–3 minutes to reduce slightly.
Make it creamy: Stir in heavy cream and remaining 1/2 teaspoon salt. Bring to a gentle simmer. Whisk in Parmesan until smooth.
Add brightness and greens: Stir in lemon juice (if using) and spinach.
Cook 1–2 minutes, until spinach wilts.
Finish the chicken: Return chicken and any juices to the pan. Spoon sauce over the top. Simmer 3–5 minutes, until chicken reaches 165°F internally and sauce thickens.
Add a pinch of red pepper flakes if you like a kick.
Serve: Taste and adjust seasoning. Garnish with chopped basil or parsley. Serve hot over zucchini noodles, steamed broccoli, or cauliflower mash.