Heat olive oil and butter in a large skillet over medium-high heat. Sear the chicken breasts until they are golden brown and cooked through with an internal temp of 165°F, about 6-7 minutes per side.
Incorporate the softened Boursin cheese, stirring continuously until the cheese melts and the sauce becomes smooth.
Return the chicken breasts along with any accumulated juices to the skillet. Spoon the creamy sauce over the chicken and let it warm through for about 2 minutes.
Garnish with fresh chopped parsley, if desired, and serve immediately.