Season and Sear Chicken:
Pat chicken dry and season both sides with salt and pepper. In a large skillet over medium heat, heat olive oil and sear chicken for 5–6 minutes per side, or until golden brown and cooked through. Transfer to a plate and set aside.
Make the Sauce:
In the same skillet, melt butter and sauté garlic for about 30 seconds. Add chicken broth and stir to deglaze the pan, scraping up any brown bits.
Add Boursin and Cream:
Stir in the Boursin cheese and let it melt into the broth. Add the cream and optional Dijon mustard. Stir until smooth and gently simmer for 3–4 minutes, letting the sauce thicken slightly.
Return Chicken to Pan:
Add the chicken back into the sauce and spoon sauce over the top. Simmer for 2–3 more minutes until heated through.
Garnish and Serve:
Sprinkle with chopped parsley and serve warm with mashed potatoes, pasta, or roasted vegetables.