Prep the chicken: Pat the chicken dry. Season both sides with 1/2 teaspoon salt, pepper, and Italian seasoning.
If using thick breasts, slice them horizontally into cutlets for faster, more even cooking.
Sear: Heat olive oil in a large skillet over medium-high. Add chicken and cook 4–6 minutes per side, until golden and cooked through (internal temp 165°F/74°C). Transfer to a plate and tent with foil.
Sauté aromatics: Reduce heat to medium.
Add garlic and sun dried tomatoes to the same pan. Cook 30–60 seconds, stirring, until fragrant. Avoid burning the garlic.
Build the sauce: Pour in chicken broth and scrape up browned bits.
Stir in heavy cream, Dijon (if using), and red pepper flakes. Bring to a gentle simmer.
Melt in the cheese: Add Parmesan and stir until smooth. Taste and season with remaining salt if needed.
If you want extra richness, swirl in the butter.
Add greens: Stir in spinach and cook 1–2 minutes, just until wilted.
Finish the dish: Return chicken (and any juices) to the pan. Spoon sauce over the top and simmer 2–3 minutes to warm through and thicken slightly.
Garnish and serve: Sprinkle with fresh basil or parsley. Serve hot with zucchini noodles, roasted broccoli, or cauliflower mash.