In a small bowl, whisk together the coconut aminos, rice vinegar, tomato paste, honey, and arrowroot powder until the mixture is smooth and well combined.
Dice the chicken breast into bite-sized pieces and season evenly with the sea salt and black pepper.
Heat the avocado oil in a large skillet or wok over medium-high heat until it begins to shimmer.
Add the chicken to the skillet and sear, stirring occasionally, until the pieces are golden brown and cooked through, approximately 5-7 minutes.
Remove the cooked chicken from the skillet and set it aside on a plate.
In the same skillet, add the diced bell peppers, broccoli florets, grated ginger, and minced garlic, sautéing for 3-4 minutes until the vegetables are tender-crisp.
Stir in the pineapple chunks and return the chicken to the skillet with the vegetables.
Pour the prepared sauce over the chicken and vegetable mixture, stirring constantly for 1-2 minutes until the glaze thickens and coats every ingredient beautifully.
Serve the sweet and sour stir-fry immediately over the warm cooked brown rice.