Pat the chicken thighs dry with paper towels. Season both sides with salt, black pepper, and garlic powder.
Heat the olive oil and 1 tablespoon butter in a large high-sided skillet over medium heat.
Add the chicken thighs skin-side down, and cook for 6 to 7 minutes until the skin is golden and crispy. Flip and cook another 5 minutes. Transfer chicken to a plate.
Reduce heat to medium-low. Add the remaining butter and minced garlic to the skillet. Cook for 30 seconds until fragrant, stirring constantly so the garlic does not burn.
Pour in the chicken broth and scrape the browned bits from the bottom of the skillet.
Stir in the heavy cream, parmesan cheese, Italian seasoning, and optional red pepper flakes. Simmer for 3 to 4 minutes until the sauce thickens slightly.
Return the chicken thighs to the skillet. Spoon sauce over the chicken and simmer for 15 to 20 minutes until the chicken is fully cooked and reaches an internal temperature of 165°F.
Remove from heat and sprinkle with fresh parsley before serving.
Notes
Bone-in, skin-on chicken thighs create the best flavor and help keep the chicken juicy during simmering.
Fresh garlic gives the sauce a much stronger flavor than jarred garlic.
Use freshly grated Parmesan for the smoothest creamy sauce texture.
If the sauce becomes too thick, stir in a splash of chicken broth before serving.
Serve with cauliflower mash, roasted broccoli, or zucchini noodles for an easy low-carb meal.
The sauce will continue to thicken slightly as it cools.
Store leftovers in an airtight container in the refrigerator for up to 3 days.