In a small bowl, whisk together the tamari, rice vinegar, honey, tomato paste, grated ginger, and minced garlic to create the sweet and sour sauce.
Cut the chicken breast into bite-sized cubes and season them evenly with the sea salt and black pepper.
Heat the avocado oil in a large skillet or wok over medium-high heat until shimmering.
Add the chicken cubes to the skillet and cook until they are golden brown and cooked through, approximately 5 to 7 minutes.
Remove the chicken from the skillet and set it aside on a plate.
In the same skillet, add the sliced red and green bell peppers along with the snap peas, stir-frying for 3 to 4 minutes until they are tender yet remain crisp.
Return the cooked chicken to the skillet and add the pineapple chunks and the prepared sauce.
Toss all the ingredients together and simmer for 1 to 2 minutes until the sauce has thickened and coated everything beautifully.
While the stir-fry finishes, steam the cauliflower rice in a separate covered pan with a splash of water until tender.
Serve the vibrant sweet and sour chicken stir-fry immediately over the warm cauliflower rice.