Pat chicken thighs dry and season both sides with salt, pepper, garlic powder, and Italian seasoning.
Heat olive oil in a large skillet over medium-high heat. Cook chicken 4–5 minutes per side until golden brown. Remove from skillet and set aside.
Reduce heat to medium. Add garlic and sauté 30 seconds. Stir in sun-dried tomatoes, bone broth, and heavy cream. Simmer 3–4 minutes.
Stir in freshly grated parmesan until melted and smooth.
Return chicken and juices to the skillet. Simmer 6–8 minutes, until chicken reaches 165°F and sauce thickens.
Stir in spinach during the last 2 minutes until wilted. Adjust salt if needed and serve warm.