01 - Preheat oven to 400°F (200°C).
02 - Pat chicken breasts dry with paper towels and 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; they do not need to be cooked through. Remove and set aside on a plate.
04 - Reduce heat to medium. In the same skillet, melt the butter. Add minced garlic and cook for 30 seconds until fragrant.
05 - Add fresh baby spinach to the skillet and sauté, tossing gently, until just wilted, about 2 minutes.
06 - Pour in the heavy cream, lemon juice, and lemon zest. Stir to combine and bring the mixture to a brief 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 skillet, pressing them into the spinach cream sauce. Spoon additional sauce over the top of each breast.
09 - Transfer the skillet to the preheated oven and bake for 12 to 15 minutes, until the chicken reaches an internal temperature of 165°F (74°C).
10 - Serve hot, garnished with extra lemon zest or shaved Parmesan if desired.