01 - Preheat oven to 400°F. Position rack in the center of the oven.
02 - Pat chicken thighs thoroughly dry with paper towels. Combine salt, pepper, smoked paprika, dried thyme, and dried basil in a small bowl, then season all sides of each thigh evenly.
03 - Melt butter in a large oven-safe skillet over medium-high heat. Place chicken thighs skin side down and sear for 3 to 4 minutes until the skin is deeply golden and crisp. Flip and sear the opposite side for 2 minutes. Transfer chicken to a plate and set aside.
04 - Reduce heat to medium. Add chopped onion to the same skillet and sauté for 2 minutes until softened. Stir in minced garlic and cook for 1 minute until fragrant. Pour in chicken broth, scraping up any browned bits from the bottom of the pan. Add heavy cream and grated Parmesan, stirring constantly until the sauce is smooth and slightly thickened.
05 - Nestle the chicken thighs back into the skillet, skin side up, spooning some of the sauce over the top. Transfer the skillet to the preheated oven and bake uncovered for 25 to 30 minutes, until the chicken reaches an internal temperature of 165°F and the sauce is bubbly.
06 - Remove from the oven, garnish with freshly chopped parsley, and serve immediately while hot.