Cut the chicken breasts in half lengthwise to create 4 thinner pieces. Season both sides of the chicken with garlic powder, salt, and black pepper, ensuring an even coating for maximum flavor.

Heat the olive oil and butter in a large skillet over medium-high heat. Once melted and hot, add the seasoned chicken and sear for about 5-6 minutes per side until golden and cooked through. Transfer the cooked chicken breasts to a plate and set aside.

Add the finely chopped onion to the same skillet and sauté over medium heat for about 5 minutes, stirring occasionally, until softened and lightly browned. If the skillet becomes dry, drizzle in a small splash of olive oil. I like to let the onions get just a touch golden for added sweetness.

To the sautéed onions, add the chicken broth and Boursin cheese. Stir gently until the cheese melts and the sauce is smooth. Allow the sauce to bubble for about 5 minutes to thicken slightly, then stir in the chopped fresh parsley, if using.

Return the cooked chicken (and any juices from the plate) back to the skillet with the sauce. Let the chicken warm through for a couple of minutes, allowing the sauce to thicken further. If the sauce is too thick, add a splash more chicken broth. Taste and adjust with additional salt and black pepper if needed. Serve immediately.