For non - Paleo (with soy sauce and cornstarch) cooking instructions, please read the notes!
Toast the sesame seeds in a dry pan over a medium heat. It will take about three minutes. You will need to stir them all the time so they don't burn and toast evenly, toss them out onto a plate once they are done.
Mix honey, coconut aminos, tomato sauce, sesame oil, garlic, and red pepper flakes together in a bowl, and mix in the arrowroot.
Season the chicken pieces with a little salt and pepper on each side.
Heat the oil in a large cast iron skillet over medium-high heat and then add the chicken pieces.
Do not crowd the pan and just do a few at a time. it will take about four minutes per side, eight minutes total.
Add the honey and coconut aminos mixture to the pan with the chicken pieces and stir well, cook for a minute or so and then turn the chicken pieces so they get coated in the sauce and cook for a further minute or two. Check that your chicken is cooked through, then remove from the heat.
Sprinkle with sesame seeds and serve hot over zoodles for paleo, or rice if you are not following paleo.
NON PALEO VERSION - for the regular gluten free version you can substitute GF soy sauce for coconut aminos, ketchup for the tomato sauce, and cornstarch for arrowroot. You can also season the chicken and then dredge it in cornstarch (shake of the excess) and then pan fry it as per the directions, and the sauce will thicken in the pan along with the chicken as it cooks. This does not work as well with arrowroot and tends to result in somewhat slimy chicken, so it's better to skip this step and simply add the arrowroot to the sauce directly.