01 - Pat the chicken thighs thoroughly dry with paper towels and season both sides generously with salt and freshly ground black pepper.
02 - Heat olive oil and butter in a large skillet over medium-high heat until the butter is melted and begins to foam.
03 - Place the chicken thighs skin side down in the skillet and sear for 5 to 6 minutes per side until the skin is deeply golden brown and crispy. 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 stir for 1 minute until fragrant.
05 - Pour in the chicken broth, using a wooden spoon to scrape up any browned bits from the bottom of the pan. 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, whisking until the sauce is smooth and well combined.
07 - Return the seared chicken thighs to the skillet, skin side up, and spoon some of the sauce over the top. Cover with a lid and simmer gently for 15 minutes, or until the chicken is cooked through to an internal temperature of 165°F and the sauce has thickened to a silky consistency.
08 - Taste the sauce and adjust seasoning with additional salt and pepper as needed. Garnish with extra chopped fresh parsley and serve immediately.