Dice the chicken breast into 1-inch cubes and season evenly with sea salt and black pepper.
In a small bowl, whisk together the tamari, rice vinegar, honey, and arrowroot powder until smooth to create the stir-fry sauce.
Heat the avocado oil in a large skillet or wok over medium-high heat until shimmering.
Add the chicken cubes to the skillet and cook for 5-6 minutes, turning occasionally, until golden brown and cooked through.
Remove the chicken from the pan and set aside on a plate.
Add the diced red and green bell peppers and red onion to the same skillet, sautéing for 3-4 minutes until they are crisp-tender.
Stir in the minced garlic, grated ginger, and pineapple chunks, cooking for another 60 seconds until fragrant.
Return the cooked chicken to the skillet and pour the prepared sauce over the mixture.
Toss everything together constantly for 1-2 minutes until the sauce thickens into a glossy glaze that coats the chicken and vegetables.