Season the chicken lightly with black pepper and a small amount of salt, keeping in mind that the ranch seasoning already contains salt.
Heat the olive oil and butter in a large skillet over medium-high heat.
Sear the chicken for 4–5 minutes per side until golden brown. Remove and set aside.
In the same skillet, sauté the garlic for 30 seconds until fragrant.
Add the chicken broth, heavy cream, cream cheese, ranch seasoning, onion powder, and Parmesan cheese. Stir until the sauce is smooth and creamy.
Return the chicken to the skillet, spoon the sauce over the top, and reduce the heat to low.
Cover and simmer for 10–15 minutes, or until the chicken reaches an internal temperature of 165°F (74°C).
Garnish with fresh parsley and serve hot with mashed potatoes, rice, pasta, or steamed vegetables.