Marinade: In a bowl add the lemon juice, olive oil or avocado oil, minced garlic, Italian seasoning, garlic powder, red pepper flakes, salt, and black pepper. Whisk to combine, then add the chicken. Use tongs to flip the chicken breasts until the chicken is completely coated on all sides.
Cover and chill for at least 30 minutes up to 2 hours. (Don't marinate overnight or longer than 2 hours as the marinade can make the chicken tough.)
Cook: Melt the butter in a large skillet or sauté pan over medium heat.
Once the butter has melted remove the chicken breasts from the marinade and add to the pan. (Reserve the marinade for the sauce.)
Increase the heat to medium-high. Cook and brown the chicken cooking for 4 minutes per side or until the juices run clear and an internal temperature of 165°F is reached. Remove from the pan and keep warm. (Cooking time may vary depending on thickness.)
To the pan add the marinade and chicken broth. Bring to a boil then lower to medium and deglaze the pan, scraping any brown bits left behind on the bottom of the pan. Add 1 Tbsp parsley, stir to combine.
Return the chicken to the sauce then use a spoon to baste with the sauce. Cook for 2-3 minutes. Remove the pan from the heat.
Sprinkle the remainder of the fresh parsley on top, then serve.