Pat the chicken breast dry with paper towels and cut into 1-inch cubes.
In a medium bowl, toss the chicken with sea salt, black pepper, and arrowroot powder until every piece is lightly coated.
Whisk together the coconut aminos, rice vinegar, honey, garlic powder, and ginger powder in a small jar to create the sauce.
Heat the avocado oil in a large non-stick skillet or wok over medium-high heat until shimmering.
Add the chicken cubes to the skillet in a single layer and sear until golden brown and crispy on all sides, about 5-6 minutes.
Remove the chicken from the pan and set aside on a plate.
Add the bell peppers, broccoli, and pineapple to the same skillet, sautéing for 3-4 minutes until the vegetables are tender-crisp.
Return the cooked chicken to the skillet and pour the sauce mixture over the ingredients.
Stir-fry constantly for 1-2 minutes until the sauce bubbles and thickens into a glossy glaze that coats the chicken and vegetables.
Serve the stir-fry immediately over the warm cooked brown rice.