In a small bowl, whisk together the coconut aminos, apple cider vinegar, tomato paste, and arrowroot powder until smooth.
Cut the chicken breast into bite-sized cubes and season with sea salt and black pepper.
Heat the avocado oil in a large skillet or wok over medium-high heat.
Add the chicken to the pan and sear until golden brown and cooked through, about 5-6 minutes, then remove from the pan and set aside.
In the same pan, add the sliced bell peppers and red onion, sautéing for 3-4 minutes until tender-crisp.
Stir in the minced garlic, grated ginger, and pineapple chunks, cooking for an additional minute until fragrant.
Return the chicken to the pan and pour the sauce over the mixture.
Toss everything together for 1-2 minutes until the sauce thickens and coats the chicken and vegetables evenly.
Serve immediately while hot.