Season the chicken breasts evenly with salt, pepper, and garlic powder.
Heat olive oil in a large skillet over medium-high heat. Sear the breasts for 6-8 minutes per side until golden brown and cooked through (internal temperature of 165F). Remove from skillet and set aside.
In the same skillet, lower the heat to medium. Pour in the heavy cream and chicken broth, whisking to scrape up any browned bits from the bottom.
Stir in the grated parmesan cheese and simmer for 2-3 minutes until the sauce begins to thicken.
Add the fresh spinach and sun-dried tomatoes, stirring gently until the spinach wilts.
Return the seared breasts to the skillet, spooning the sauce over them. Garnish with chopped fresh parsley before serving.