Pat the chicken breast dry with paper towels and cut into bite-sized cubes.
In a small bowl, toss the chicken with arrowroot powder, sea salt, and black pepper until evenly coated.
Prepare the sauce by whisking together the orange juice, coconut aminos, minced ginger, and minced garlic in a separate small bowl.
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 chicken from the pan and set aside.
Add the broccoli florets and sliced red bell pepper to the same skillet with a tablespoon of water, covering for 2 minutes to steam-fry until tender-crisp.
Return the chicken to the skillet and pour the orange sauce over the mixture.
Stir constantly for 1-2 minutes until the sauce thickens into a glossy glaze that coats the chicken and vegetables.
Garnish with sesame seeds and serve immediately.