Prepare the Chicken: Place chicken breasts between two sheets of parchment paper or plastic wrap and gently pound to even ½ inch thickness. Season both sides generously with salt, pepper, and garlic powder.

Sear for a Golden Crust: Heat olive oil in a large skillet over medium-high heat. Place seasoned chicken in the hot pan without overcrowding. Cook undisturbed for 4 to 6 minutes per side until golden brown and cooked through. Transfer chicken to a plate and set aside.

Build the Flavor Base: Reduce heat to medium and melt butter in the same skillet. Add minced garlic and cook for 30 to 60 seconds until fragrant. Add chopped sun-dried tomatoes, oregano, and red pepper flakes (if using). Stir for about a minute until tomatoes soften.

Deglaze and Create the Sauce: Pour in white wine or chicken broth. Scrape up browned bits from the bottom of the pan. Let liquid simmer and reduce by half, about 2 to 3 minutes.

Make It Creamy: Reduce heat to low and pour in heavy cream. Stir gently and simmer for a couple of minutes until slightly thickened.

Wilt the Greens and Melt the Cheese: Stir in Parmesan until melted into the sauce. Add spinach in large handfuls and stir until wilted, about 1 to 2 minutes.

Bring It All Together: Return chicken and any accumulated juices to the skillet. Let simmer together for 1–2 minutes to absorb flavors. Add lemon juice if desired. Garnish with fresh basil or parsley and serve immediately.