In a small bowl, whisk together the coconut aminos, rice vinegar, tomato paste, honey, and arrowroot powder until the sauce is smooth.
Season the diced chicken breast evenly with the sea salt and black pepper.
Heat the avocado oil in a large skillet or wok over medium-high heat until shimmering.
Add the chicken to the skillet and sear until golden brown and cooked through, then remove from the pan and set aside.
In the same skillet, add the red onion, red bell pepper, and green bell pepper, sautéing for about 4 minutes until they are tender-crisp.
Stir in the minced garlic, grated ginger, and pineapple chunks, cooking for another 2 minutes until the aromatics are fragrant.
Return the cooked chicken to the pan and pour the prepared sauce over the mixture.
Stir constantly for 1-2 minutes until the sauce thickens into a glossy glaze that coats the chicken and vegetables.