Pat the chicken breast dry with a paper towel and toss in a bowl with arrowroot powder, sea salt, and black pepper until evenly coated.
In a small mixing bowl, whisk together the pineapple juice, coconut aminos, rice vinegar, minced ginger, and minced garlic to create the sauce.
Heat 1 teaspoon of avocado oil in a large non-stick skillet or wok over medium-high heat. Add the chicken and sear until golden brown and cooked through, about 5-6 minutes, then remove and set aside.
Add the remaining teaspoon of avocado oil to the same skillet. Toss in the sliced bell peppers, broccoli florets, and snap peas, sautéing for 3-4 minutes until they are tender-crisp and bright.
Return the cooked chicken to the skillet and pour the sauce over the mixture. Stir constantly for 1-2 minutes until the sauce thickens into a glossy glaze that coats everything.
Serve the stir-fry immediately over a bed of steamed cauliflower rice for a high-volume, nutrient-dense meal.