Prep the chicken: Pat the chicken dry and season both sides with salt and pepper. If using breasts, pound to an even 1/2–3/4 inch thickness so they cook evenly.
Sear for flavor: Heat olive oil in a large skillet over medium-high heat. Sear chicken 4–5 minutes per side until golden.
Remove to a plate; it will finish in the sauce.
Build the base: Lower heat to medium. Add butter, then garlic and red pepper flakes. Sauté 30–45 seconds until fragrant, not browned.
Add tomatoes and deglaze: Stir in sun-dried tomatoes.
Pour in chicken broth (and white wine if using). Scrape the browned bits from the pan—this is your flavor bomb.
Creamy finish: Stir in heavy cream, Parmesan, and Italian seasoning. Simmer 2–3 minutes, stirring, until the sauce slightly thickens and the cheese melts.
Nestle chicken back in: Return chicken and any juices to the skillet.
Spoon sauce over the pieces. Simmer gently 5–7 minutes until the chicken is cooked through (165°F internal).
Adjust and brighten: Taste and add salt, pepper, or a pinch more red pepper flakes. Stir in fresh basil.
If using spinach, fold it in now until just wilted.
Serve: Plate with sauce over zucchini noodles, spaghetti squash, cauliflower mash, roasted green beans, or a simple arugula salad.