Pat the chicken breast dry with a paper towel and toss in a bowl with arrowroot starch, sea salt, and black pepper until evenly coated.
Heat the avocado oil in a large skillet or wok over medium-high heat until shimmering.
Add the chicken to the pan and sear for 5-6 minutes, turning occasionally, until golden brown and cooked through, then transfer to a plate.
Lower the heat to medium, add the toasted sesame oil to the same pan, and sauté the broccoli, red bell pepper, fresh ginger, and garlic for 3-4 minutes.
Stir in the cauliflower rice and coconut aminos, cooking for an additional 2-3 minutes until the vegetables are tender yet still crisp.
Return the cooked chicken to the pan, toss everything together to coat in the glaze, and serve immediately garnished with sesame seeds.