Season chicken thighs on both sides with salt, pepper, and garlic powder.
Heat olive oil in a large skillet over medium-high heat.
Place chicken skin-side down in the skillet and sear for 6 minutes until crispy and golden. Flip and cook for an additional 3 minutes, then remove chicken from pan and set aside.
In the same skillet, add sliced mushrooms and onions. Sauté for 5 to 7 minutes until the onions are translucent and mushrooms have browned.
Add minced garlic and cook for 60 seconds until fragrant.
Pour in chicken broth to deglaze the pan, scraping up any browned bits from the bottom.
Stir in the heavy cream and dried thyme. Bring the liquid to a gentle simmer.
Return the chicken thighs to the skillet. Reduce heat to medium-low and simmer for 10 to 12 minutes until the sauce has thickened and the chicken reaches an internal temperature of 165°F (74°C).
Stir in the Parmesan cheese until melted and garnish with fresh parsley before serving.