Preheat the oven to 450 degrees F.

Wash the Brussels sprouts, trim off the ends, and slice in half. Grease a baking sheet with the avocado/olive oil and spread Brussels sprouts out on the pan. Bake for 10 minutes. After 10 minutes, add the chicken to the baking sheet and bake for another 10 minutes (a total baking time of 20 minutes) or until chicken is cooked through.

While these are baking, prepare the sauce by whisking together the tamari/soy, vinegar, honey, garlic, ginger, and sesame oil in a saucepan. Bring to a boil. While this is coming to temperature, whisk the arrowroot powder and water in a small bowl until there are no lumps. Whisk this into the saucepan as soon as the sauce comes to boil. Turn the heat to medium and cook for 2 minutes, stirring frequently as it again comes to a boil. Sauce should start to thicken.

Remove from heat when thick and set aside; it will continue to thicken as it sits. When chicken and Brussels are done, let cool before mixing with the sauce. I like to let them both cool as the sauce will get nice and sticky, perfect for serving. Garnish with sesame seeds or green onions as desired and serve atop rice.