Pat the chicken breast dry with paper towels and cut into bite-sized pieces.
Place chicken in a bowl and toss with arrowroot powder, sea salt, and black pepper until evenly coated.
In a small jar or bowl, whisk together the tamari, rice vinegar, honey, tomato paste, minced ginger, and minced garlic to create the sauce.
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, then add the bell peppers and broccoli florets to the same pan.
Sauté the vegetables for 3-4 minutes until they are tender-crisp and bright.
Return the chicken to the pan along with the pineapple chunks.
Pour the sauce over the mixture and toss constantly for 1-2 minutes until the glaze thickens and coats every piece.
Serve immediately while hot and glossy.