Cut the chicken breast into bite-sized cubes and season evenly with sea salt and black pepper.
In a small glass bowl, whisk together the coconut aminos, rice vinegar, tomato paste, and arrowroot powder until the mixture is smooth.
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 until golden brown and cooked through, approximately 5 to 7 minutes, then remove chicken and set aside.
In the same skillet, add the chopped bell peppers, red onion, minced garlic, and grated ginger, sautéing for 3 to 4 minutes until the vegetables are tender-crisp.
Stir in the fresh pineapple chunks and pour the prepared sauce over the vegetables, stirring constantly as the sauce begins to bubble and thicken.
Return the cooked chicken to the skillet, tossing thoroughly to ensure every piece is coated in the glossy glaze before serving warm.