Pat chicken thighs dry and press slightly flatter for even cooking. Season one side with garlic powder, salt, and black pepper. Set aside.
In a saucepan over medium low heat, add avocado oil. Stir in ginger and garlic and cook until fragrant, about 3 minutes.
Add coconut aminos, mirin, and sake. Bring to a boil for 5 minutes to cook off the alcohol, then reduce to a simmer and cook until reduced by about two thirds.
Whisk the cornstarch with water to create a smooth slurry. With the sauce at a steady simmer, slowly pour it in while stirring constantly. Continue cooking for 1 to 2 minutes until the sauce thickens, turns glossy, and coats the back of a spoon. Remove from heat and stir in the rice vinegar and sesame seeds.
Coat chicken in a light layer of the teriyaki sauce, don't use all of the sauce.
Preheat air fryer to 400°F (200°C). Lightly spray basket with olive oil. Cook chicken in a single layer for about 15 minutes, flipping half way, or until caramelized and cooked through. Let rest, then slice.
Meanwhile, combine rice and water in a saucepan. Bring to a boil, then reduce to low, cover, and simmer 15 to 20 minutes until fluffy.
Sauté broccoli in a skillet with a small amount of oil until bright green and slightly charred.
Assemble bowls with rice, broccoli, sliced chicken, and drizzle with teriyaki sauce.