Place each chicken breast between two pieces of parchment paper or plastic wrap. Use a meat mallet or rolling pin to pound the chicken to an even thickness.

Season both sides of the chicken breasts with kosher salt, freshly ground pepper, and 1 teaspoon of Italian seasoning.

Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Once hot, gently place the chicken breasts into the skillet and sear for approximately 3-4 minutes on each side until golden brown.

Remove the chicken from the skillet and transfer to a plate to rest.

In the same skillet, lower the heat and add the remaining tablespoon of olive oil. After it warms slightly, add the diced onion and sauté for about 2-3 minutes until the onion becomes translucent.

Add the minced garlic and sun-dried tomatoes, cooking for an additional minute until fragrant.

Sauté the baby spinach until it wilts down, about 1-2 minutes.

Pour the heavy cream into the skillet and add in the remaining teaspoon of Italian seasoning and freshly grated parmesan cheese. Stir and allow to simmer for about a minute.

Nestle the seared chicken back into the creamy mixture, bring to a gentle simmer, reduce heat to medium-low, and cook for an additional 5-6 minutes until the chicken is fully cooked through.

Remove from heat and top with extra parmesan if desired. Serve immediately with your preferred sides.