Season the chicken breasts with salt, pepper, onion powder, thyme, and rosemary on both sides.
In a large skillet, heat olive oil over medium-high heat. Once hot, add the chicken breasts and sear for about 5-6 minutes on each side until golden brown and cooked through. Remove the chicken from the skillet and set aside.
In the same skillet, add the minced garlic and sauté for about 1 minute until fragrant. Be careful not to burn the garlic.
Pour in the chicken broth, scraping the bottom of the skillet to deglaze it. Then, lower the heat and stir in the heavy cream. Bring to a gentle simmer.
Add the grated Parmesan cheese to the cream mixture, stirring constantly until it melts and the sauce thickens slightly.
Stir in the chopped spinach, and let it cook for an additional 2-3 minutes until wilted.
Return the cooked chicken breasts to the skillet, spooning the creamy sauce over them. Let it simmer for another minute to warm the chicken through.
Taste and adjust seasoning if necessary.
Garnish with fresh parsley before serving.
Notes
Serve with roasted vegetables or garlic bread for a complete meal.