Preheat and prep: Heat your oven to 375°F (190°C).
Pat the chicken dry with paper towels so it sears well.
Season the chicken: In a small bowl, mix ranch seasoning, garlic powder, paprika, 1/2 teaspoon salt, and 1/2 teaspoon black pepper. Sprinkle evenly over both sides of the chicken.
Sear for flavor: Heat a large oven-safe skillet over medium-high heat. Add oil and 1 tablespoon butter.
When hot, add chicken and sear 3–4 minutes per side until golden. Don’t cook through yet. Transfer chicken to a plate.
Build the sauce base: Reduce heat to medium.
Add remaining 1 tablespoon butter to the skillet. Pour in chicken broth and scrape the browned bits with a wooden spoon. Let it simmer 2 minutes to reduce slightly.
Make it creamy: Lower heat and stir in cream (or half-and-half).
If using Parmesan, whisk it in until smooth. Taste and adjust salt and pepper. The sauce should be well-seasoned and slightly thickened.
Return chicken to the pan: Nestle the chicken into the sauce.
Spoon some sauce on top of each piece. If using lemon juice, drizzle it in now for brightness.
Bake: Transfer the skillet to the oven. Bake 12–18 minutes, depending on thickness, until the internal temperature reaches 165°F (74°C).
Rest and garnish: Let the chicken rest 5 minutes in the sauce.
Sprinkle with chopped parsley or chives.
Serve: Spoon extra sauce over the chicken. Pair with mashed potatoes, buttered noodles, rice, or roasted green beans.