Prepare the chicken by slicing horizontally or pounding between plastic wrap to an even 1/2-inch thickness. Season both sides generously with salt, pepper, and paprika if using.

Drain the artichoke hearts and roughly chop them. Wash and dry the spinach. Mince the garlic. Set all ingredients within reach.

Heat 1 tablespoon olive oil and 1 tablespoon butter in a large skillet over medium-high heat. Once shimmering, add the chicken breasts. Cook for 3-4 minutes per side, until golden brown and cooked through (internal temperature 165°F). Remove to a plate and tent with foil.

Reduce heat to medium-low. Add the remaining tablespoon of butter if needed. Add the minced garlic and sauté for 60 seconds until fragrant, stirring constantly to prevent burning.

Add the cubed cream cheese and chicken broth to the pan. Stir constantly, scraping up the browned bits (fond) from the bottom. Once the cream cheese melts and the mixture is smooth, pour in the heavy cream and stir well.

Bring the sauce to a gentle simmer. Add the chopped artichoke hearts and grated Parmesan cheese. Stir until the Parmesan is fully melted and the sauce is smooth and slightly bubbling.

Add the fresh baby spinach, a handful at a time, folding it into the sauce. The spinach wilts quickly, usually within 2 minutes. Stir in the lemon juice and red pepper flakes if using. Taste and adjust seasoning with salt and pepper.

Return the seared chicken breasts to the skillet, nestling them into the sauce. Spoon some sauce over the top of the chicken to ensure it's fully coated. Let it simmer gently for 2-3 minutes to heat the chicken through and allow the flavors to meld.

Serve immediately, garnished with extra Parmesan and chopped parsley if desired. Pair with pasta, rice, or mashed potatoes for a complete meal.