Start by seasoning both sides of the chicken breasts generously with kosher salt and black pepper. To ensure even cooking, I recommend pounding the chicken to an even thickness. This step helps avoid undercooked or rubbery spots, making your chicken tender and juicy throughout.

Heat your skillet over medium. Once warm, add in the olive oil. Place the seasoned chicken breasts into the skillet and cook for 5-8 minutes per side until golden brown. Check that the internal temperature reaches 165°F, then transfer the chicken to a plate and cover it loosely with foil to keep warm.

With the skillet still warm, pour in the chicken stock, deglazing the pan to scrape up all the flavorful brown bits. These bits are key to building a rich sauce. Add the Boursin cheese into the stock. Use a spoon or spatula to break up the cheese, stirring until melted and the sauce is smooth.

If using fresh spinach, toss it into the sauce and stir gently. The spinach will wilt quickly from the heat. This step is optional but adds a nutritious touch to the dish.

Return the seared chicken to the skillet, spooning the Boursin sauce over each piece. Cover and simmer on low for a couple of minutes to warm everything through. Serve hot, drizzled generously with the sauce.