01 - Preheat oven to 400°F (200°C).
02 - Pat chicken breasts dry with paper towels. Season both sides generously with salt, freshly ground black pepper, and dried Italian herbs.
03 - Heat olive oil in a large oven-safe skillet over medium-high heat. Sear the chicken breasts for 3–4 minutes per side until a golden crust forms. Remove from the skillet and set aside on a plate.
04 - Reduce heat to medium. Add unsalted butter to the skillet and let it melt. Sauté the minced garlic for about 1 minute until fragrant, being careful not to brown it.
05 - Add the fresh baby spinach to the skillet. Cook, stirring frequently, for approximately 2 minutes until the spinach is fully wilted.
06 - Pour in the heavy cream and stir in the freshly grated Parmesan cheese, lemon zest, and lemon juice. Simmer the sauce for 1–2 minutes, stirring constantly, until it slightly thickens and coats the back of a spoon.
07 - Nestle the seared chicken breasts back into the skillet, spooning the creamy spinach sauce over the top of each piece.
08 - Transfer the skillet to the preheated oven. Bake for 12–15 minutes, or until the chicken reaches an internal temperature of 165°F (74°C) and is cooked through completely.
09 - Remove from the oven and serve hot, garnished with additional freshly grated Parmesan cheese and lemon slices if desired.