01 - Pat the chicken thighs thoroughly dry with paper towels. Season both sides generously with salt and freshly ground black pepper.
02 - Heat olive oil and butter together in a large skillet over medium-high heat until the butter is melted and beginning to foam.
03 - Place the chicken thighs skin side down in the skillet. Sear for 5 to 6 minutes per side until the skin is deeply golden brown and crisp. Transfer the chicken to a plate and set aside.
04 - In the same skillet, add the diced onion and cook for 2 to 3 minutes until softened and translucent. Add the minced garlic and cook for 1 minute until fragrant, stirring constantly to prevent burning.
05 - Pour in the chicken broth, scraping up all the browned bits from the bottom of the pan with a wooden spoon. Let the liquid reduce slightly for about 1 minute.
06 - Reduce the heat to medium-low. Stir in the heavy cream, dried thyme, dried rosemary, dried oregano, and chopped parsley. Mix until the sauce is smooth and well combined.
07 - Return the seared chicken thighs to the skillet, placing them skin side up. Spoon some of the cream sauce over the top of each thigh.
08 - Cover the skillet with a lid and reduce the heat to a gentle simmer. Cook for 15 minutes, or until the chicken reaches an internal temperature of 165°F and the sauce has thickened to a luscious consistency.
09 - Taste the sauce and adjust the seasoning with additional salt and pepper if needed. Garnish generously with extra fresh parsley and serve immediately.