Pat the chicken breast dry with paper towels and cut into bite-sized cubes.
Place the chicken in a bowl and toss with arrowroot powder, sea salt, and black pepper until every piece is evenly coated.
In a small jar or bowl, whisk together the tamari, rice vinegar, honey, sesame oil, grated ginger, and minced garlic to create the stir-fry sauce.
Heat the avocado oil in a large non-stick skillet or wok over medium-high heat.
Add the chicken to the pan in a single layer and sear for 3-4 minutes per side until golden brown and crispy.
Remove the chicken from the pan and set aside on a plate.
Add the bell peppers, broccoli, and pineapple to the same pan, sautéing for 4-5 minutes until the vegetables are tender-crisp.
Return the crispy chicken to the pan and pour the prepared sauce over the mixture.
Toss everything together for 1-2 minutes until the sauce thickens into a glossy glaze that coats the chicken and vegetables.