Dice the chicken into bite-sized pieces and toss in a bowl with arrowroot starch, sea salt, and black pepper until evenly coated.
In a small bowl, whisk together the tomato puree, tamari, apple cider vinegar, and honey to create the sweet and sour sauce.
Heat the avocado oil in a large skillet or wok over medium-high heat until shimmering.
Add the chicken to the skillet, cooking for 5-6 minutes until golden brown and crispy on all sides, then remove and set aside.
In the same skillet, add the sliced bell peppers, snap peas, and red onion, sautéing for 3-4 minutes until tender-crisp.
Return the chicken to the pan and pour the sauce over the mixture, tossing constantly for 1 minute until the glaze thickens and coats everything.
Serve the crispy stir-fry immediately over steamed cauliflower rice for a clean, nutrient-dense meal.