Pat the chicken dry and season generously with salt, pepper, and half of the Italian seasoning. This helps create a crisp, flavorful crust as it sears.
In a large, heavy skillet, heat olive oil over medium-high heat. Add the chicken thighs, skin-side down, and sear until the skin is golden and crisp, about 5-6 minutes. Flip and sear the other side for 3-4 minutes. Remove the chicken from the skillet and set aside.
Add the halved potatoes to the same skillet in a single layer. Let them brown on one side without moving for 3-4 minutes, then toss to coat and cook for another 3-4 minutes until the edges are slightly crisp. If needed, add a touch more oil.
Stir in the minced garlic and remaining Italian seasoning, cooking for about 30 seconds until fragrant. Pour in the chicken broth to deglaze the pan, scraping up any browned bits from the bottom.
Return the chicken to the skillet, add sun-dried tomatoes, and pour in the cream. Bring to a gentle simmer, then reduce heat to medium-low. Simmer for 8-10 minutes, or until the potatoes are tender and the chicken reaches an internal temperature of 165°F (74°C).
Stir in Parmesan cheese and spinach in batches, allowing the leaves to wilt before adding more. Once the spinach is fully wilted and glossy, taste and adjust seasoning with salt and pepper. Remove from heat and let rest for a few minutes before serving to let flavors meld.