Prepare the Chicken: Season the chicken thighs generously with salt and pepper on both sides.
Sear the Chicken: In a large skillet, heat the olive oil over medium-high heat. Add the chicken thighs, skin-side down, and sear them for about 5-7 minutes until golden brown. Flip the chicken and sear the other side for an additional 5 minutes. Remove the chicken from the skillet and set aside.
Sauté Aromatics: In the same skillet, lower the heat to medium and add the chopped onion. Sauté for 3-4 minutes until translucent. Add the minced garlic and sliced mushrooms, cooking for another 5 minutes until the mushrooms are tender.
Make the Sauce: Pour in the chicken broth, scraping the bottom of the skillet to release any browned bits. Stir in the heavy cream and dried thyme. Season with salt and pepper to taste.
Combine Everything: Return the chicken thighs to the skillet, skin-side up, ensuring they are covered with the creamy sauce. Bring to a simmer, then reduce the heat to low. Cover the skillet and cook for about 25-30 minutes, or until the chicken is cooked through and tender.
Serve: Once cooked, remove from heat and let it sit for a minute. Garnish with fresh chopped parsley before serving.