Begin by gathering all your ingredients. Cut the red onion into slivers and have your mushrooms ready. If you haven’t purchased pre-sliced mushrooms, take a moment to slice them up.
Pat the chicken thighs dry with paper towels. Season both sides generously with salt and pepper. This simple step enhances the flavor and helps achieve a crispy skin.
In a large skillet, heat the olive oil over medium-high heat. Once the oil is shimmering, it’s time to add the chicken.
Place the chicken thighs skin-side down in the hot skillet. Cook for about 5-7 minutes until the skin is golden brown and crispy. Flip the chicken over and cook for an additional 5 minutes. This creates a beautiful crust that locks in moisture.
Once the chicken is seared, remove it from the skillet and set it aside. In the same pan, add the slivered onions and sliced mushrooms. Sauté for about 5 minutes until the onions are translucent and the mushrooms have released their juices.
Nestle the seared chicken thighs back into the skillet with the onions and mushrooms. Sprinkle the ground rosemary over the top, then cover the pan and reduce the heat to medium-low. Cook for an additional 20-25 minutes, or until the chicken reaches an internal temperature of 165°F.
Once cooked, remove the skillet from heat. If desired, sprinkle fresh chopped parsley over the dish for a pop of color and freshness. Serve it hot with your favorite side dishes, such as rice, mashed potatoes, or a simple green salad.