Dice the chicken breast into 1-inch cubes and season evenly with sea salt and black pepper.
In a small mixing bowl, whisk together the coconut aminos, apple cider vinegar, honey, tomato paste, minced ginger, and minced garlic to create the sauce.
Heat the avocado oil in a large skillet or wok over medium-high heat.
Add the seasoned chicken cubes to the skillet and sauté until they are golden brown and cooked through, approximately 5 to 7 minutes.
Remove the cooked chicken from the skillet and set it aside on a plate.
In the same skillet, add the diced red and green bell peppers along with the red onion, and sauté for 3 to 4 minutes until tender-crisp.
Stir in the fresh pineapple chunks and cook for an additional 2 minutes until they begin to soften and slightly caramelize.
Return the cooked chicken to the skillet and pour the prepared sauce over the chicken and vegetable mixture.
Toss everything together for 1 to 2 minutes until the sauce has thickened slightly and coats all ingredients thoroughly.
Serve the sweet and sour chicken immediately over a bed of steamed cauliflower rice.