Cut the chicken breast into bite-sized pieces and toss in a bowl with arrowroot powder, sea salt, and black pepper until evenly coated.
Heat the avocado oil in a large skillet or wok over medium-high heat.
Add the chicken to the skillet and sear for 5-6 minutes, turning occasionally, until golden brown and cooked through.
Remove the chicken from the pan and set aside; add the broccoli florets and sliced red bell pepper to the same pan.
Sauté the vegetables for 3-4 minutes until they are vibrant and crisp-tender, adding a splash of water if needed to steam.
In a small jar, whisk together the fresh orange juice, coconut aminos, minced ginger, and minced garlic.
Return the chicken to the skillet and pour the orange sauce over the mixture.
Stir-fry for 1-2 minutes until the glaze thickens and coats the chicken and vegetables thoroughly.
Serve the stir-fry immediately over the warm cooked brown rice and garnish with sesame seeds.