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 2-3 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.
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.
08 - Nestle the seared chicken breasts back into the spinach cream sauce, spooning some sauce over the top of each piece.
09 - Transfer the skillet to the oven and bake for 12-15 minutes, until chicken reaches an internal temperature of 165°F.
10 - Serve hot directly from the skillet, garnished with additional lemon zest or shaved Parmesan if desired.