01 - Season the chicken breasts on both sides with kosher salt and freshly ground black pepper, ensuring even coverage.
02 - Heat olive oil in a large skillet over medium-high heat. Add chicken breasts and sear for 4 to 5 minutes on each side until golden brown and nearly cooked through. Transfer to a plate and cover loosely with foil.
03 - In the same skillet, reduce heat to medium. Add diced onion and cook for 2 to 3 minutes until softened. Stir in minced garlic and cook for 30 seconds until fragrant.
04 - Add fresh baby spinach and sauté until just wilted, about 1 minute. Stir in quartered artichoke hearts.
05 - Pour in chicken broth, scraping up any browned bits from the bottom of the skillet. Add heavy cream, grated Parmesan, Dijon mustard, and red pepper flakes. Stir to combine and bring to a gentle simmer.
06 - Return chicken breasts to the skillet, nestling them into the sauce. Simmer on low for 6 to 8 minutes, or until chicken is cooked through and sauce has slightly thickened.
07 - Sprinkle with chopped fresh parsley before serving.