In a large mixing bowl combine the avocado oil with the minced garlic, lemon juice, chili flakes, paprika, oregano, Erythritol, vinegar, salt and pepper. Whisk well and add the chicken breasts.
Coat all the chicken pieces evenly with the mixture and allow to marinate for a minimum of one hour.
Heat the butter in a non-stick frying pan or skillet and cook the chicken over medium heat, for 7-10 minutes on each side, until completely cooked through and slightly charred.