Cook the brown rice according to package instructions and set aside.
In a small bowl, whisk together the coconut aminos, rice vinegar, honey, and arrowroot powder until smooth.
Season the diced chicken breast with sea salt and black pepper.
Heat the toasted sesame oil in a large skillet or wok over medium-high heat.
Add the chicken to the skillet and sear until golden brown and cooked through, about 5-7 minutes.
Stir in the minced garlic and grated ginger, cooking for 1 minute until fragrant.
Add the sliced bell peppers and snap peas, sautéing for 3-4 minutes until tender-crisp.
Add the pineapple chunks and the prepared sauce to the skillet.
Toss everything together for 1-2 minutes until the sauce has thickened and coated the ingredients.
Serve the sweet and sour stir-fry over the cooked brown rice.