Dice the chicken breast into bite-sized pieces and season evenly with sea salt and black pepper.
In a small glass bowl, whisk together the coconut aminos, apple cider vinegar, honey, and arrowroot powder until smooth.
Heat the avocado oil in a large skillet or wok over medium-high heat until shimmering.
Add the chicken pieces to the skillet and cook for 5-6 minutes, stirring occasionally, until golden brown and cooked through.
Remove the chicken from the skillet and set aside on a plate.
Add the sliced red bell pepper, green bell pepper, and red onion to the same skillet, sautéing for 3-4 minutes until tender-crisp.
Stir in the fresh pineapple chunks and cook for an additional minute to warm through.
Return the cooked chicken to the skillet 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.
Remove from heat and garnish with sesame seeds before serving hot.