Pat the chicken breast dry and cut into 1-inch cubes; season with sea salt, black pepper, garlic powder, and ground ginger.
In a small bowl, whisk together the pineapple juice, tamari, rice vinegar, and honey to create the sweet and sour sauce.
Heat avocado oil in a large skillet or wok over medium-high heat until shimmering.
Add the chicken to the skillet in a single layer and sear for 5-6 minutes, turning occasionally, until golden brown and cooked through.
Remove chicken from the pan and set aside; add red bell peppers, snap peas, and broccoli to the same skillet.
Stir-fry the vegetables for 3-4 minutes until tender-crisp and bright in color.
Return the chicken to the pan and pour the sauce over the mixture, tossing constantly for 1-2 minutes until the glaze thickens and coats everything.
Serve the crispy stir-fry immediately over a bed of warm brown rice.