01 - Preheat oven to 400°F.
02 - Pat chicken breasts dry; season both sides generously with salt, pepper, and dried Italian herbs.
03 - Heat olive oil in a large oven-safe skillet over medium-high heat. Sear the chicken for 3 to 4 minutes per side, until a golden crust forms. Remove and set aside.
04 - Reduce heat to medium and add butter to the same skillet. Sauté the minced garlic for 1 minute until fragrant.
05 - Add fresh spinach to the skillet, stirring constantly until wilted, about 2 minutes.
06 - Stir in heavy cream, Parmesan cheese, lemon zest, and lemon juice. Simmer for 1 to 2 minutes until the sauce slightly thickens.
07 - Return the seared chicken to the skillet, spooning the sauce over the top to coat evenly.
08 - Transfer the skillet to the oven. Bake for 12 to 15 minutes, until the internal temperature of the chicken reaches 165°F.
09 - Serve hot, garnished with extra Parmesan and fresh lemon slices if desired.