Dice the chicken breast into bite-sized pieces and season with sea salt and black pepper.
In a small bowl, whisk together the coconut aminos, rice vinegar, honey, and arrowroot powder to create the sauce.
Heat the avocado oil in a large skillet or wok over medium-high heat.
Add the chicken to the skillet and cook until golden brown and cooked through, approximately 5 to 7 minutes.
Remove the chicken from the pan and set aside; add the bell peppers, red onion, and pineapple chunks to the same skillet.
Stir-fry the vegetables and fruit for 3 to 4 minutes until the peppers are tender-crisp.
Return the chicken to the skillet and pour the prepared sauce over the mixture, stirring constantly until the sauce becomes thick and glossy.
Sauté the cauliflower rice in a separate pan over medium heat for 5 minutes until tender.
Serve the sweet and sour stir-fry over the cauliflower rice and garnish with sesame seeds.