Pat chicken breasts dry and season evenly with salt, black pepper, paprika, garlic powder, and Italian seasoning.
Heat olive oil in a skillet over medium-high heat and sear chicken for 5 to 6 minutes on each side until golden brown. Remove chicken and set aside.
In the same skillet, add minced garlic and sun-dried tomatoes and sauté for 30 seconds until fragrant.
Pour in chicken broth and scrape the bottom of the pan to loosen browned bits.
Add heavy cream, Dijon mustard, dried oregano, and red pepper flakes if using, then simmer for 3 to 4 minutes.
Stir in grated Parmesan cheese until the sauce is smooth and creamy.
Return the chicken breasts to the pan and simmer for 5 minutes until the sauce thickens and coats the chicken.
Garnish with fresh basil or parsley, and serve over pasta, rice, or mashed potatoes as desired.