Preheat oven to 400°
Make garlic butter sauce by combining butter, parsley, Italian seasoning and 4 cloves minced garlic. Stir together and set aside.
Cover the bottom of a large cast iron skillet with olive oil.
Heat oil over medium high heat.
Season chicken breasts on both sides with salt, pepper and smoked paprika to taste.
When skillet is hot, sear chicken breasts for 2-3 minutes per side.
Before flipping chicken breasts, add 2 cloves minced garlic and minced onion.
After flipping breasts add red onion.
Once chicken breasts are seared to a golden color on both sides, pour butter sauce over them. Flip chicken breasts one more time to coat.
(I added broccoli and bell peppers to the skillet at this point, but that is optional!)
Remove skillet from heat and place in oven.
Bake for 20 – 25 minutes, or until chicken reaches an internal temperature of 165° and is no longer pink. Do not overcook or your chicken will dry out. I recommend checking your chicken after 20 minutes and then continuing to cook for another 5 minutes if it isn’t done.
Allow chicken to rest for 5 minutes before serving.