01 - Preheat oven to 400°F. Position rack in the center.
02 - Pat chicken breasts dry with paper towels. Season both sides evenly with salt, pepper, and dried Italian herbs.
03 - Heat olive oil in a large oven-proof skillet over medium-high heat. Sear chicken breasts for 2 to 3 minutes per side until a golden crust forms. Remove and set aside; they will finish cooking in the oven.
04 - Reduce heat to medium. Melt butter in the same skillet. Add minced garlic and cook for 30 seconds until fragrant, stirring constantly to prevent burning.
05 - Add fresh spinach to the skillet and sauté, tossing gently, until just wilted, about 2 minutes.
06 - Pour in heavy cream, lemon juice, and lemon zest. Stir to combine and bring briefly to a simmer.
07 - Sprinkle in the grated Parmesan cheese and stir continuously until melted and the sauce thickens slightly, about 1 minute.
08 - Return chicken breasts to the skillet, nestling them into the spinach cream sauce. Spoon sauce over the top. Transfer skillet to the oven and bake for 12 to 15 minutes until chicken reaches an internal temperature of 165°F.
09 - Remove from oven and serve hot, garnished with additional lemon zest or shaved Parmesan if desired.