Stir the ingredients for the marinade together in a small bowl (avocado oil, lemon juice, lemon zest, garlic, parsley, oregano, thyme, sea salt, and pepper) until well-combined.

Transfer the boneless chicken breasts to a large zip lock bag and pour the Greek dressing marinade into the bag with the chicken. Seal the bag and move everything around until the breasts are well-coated in the marinade. Refrigerate for at least 15 minutes, ideally several hours (up to 12 hours).

When you’re ready to bake the chicken, preheat the oven to 350 degrees Fahrenheit. Transfer the marinated chicken to a casserole dish, roasting pan, or rimmed baking sheet including the Greek marinade.

Bake on the center rack of the preheated oven for 12 minutes, then change your oven setting to High Broil and broil for 5 minutes.

Remove the chicken from the oven, and use a meat thermometer to check the internal temperature of the chicken. Chicken breasts are fully cooked once they reach an internal temperature of 165 degrees F. The exact cooking time will depend on the thickness of the chicken breasts and the temperature of them before they go into the oven.

Allow the chicken to rest for 10 minutes before serving with your favorite healthy side dishes. Serve the chicken with tzatziki sauce if you like it!