Pat the chicken breast dry with paper towels and toss in a bowl with arrowroot powder, sea salt, and black pepper until evenly coated.
Heat the avocado oil in a large skillet over medium-high heat until shimmering.
Add the chicken to the skillet and sear until golden brown and cooked through, about 6-8 minutes, then remove and set aside.
In the same skillet, sauté the chopped red bell pepper, snap peas, and pineapple chunks for 3-4 minutes until tender-crisp.
In a small bowl, whisk together the coconut aminos, rice vinegar, honey, grated fresh ginger, and minced garlic.
Return the chicken to the pan and pour the sauce over the mixture, stirring constantly for 1-2 minutes until the sauce becomes thick and glossy.
Serve the stir-fry immediately over a bed of steamed cauliflower rice.