Slice the chicken breast into even 1-inch cubes and season them thoroughly with sea salt and black pepper.
In a small mixing bowl, whisk together the orange juice, tamari, honey, minced fresh ginger, and minced garlic to create the base sauce.
In a separate small ramekin, stir the arrowroot powder and water together until a smooth, milky slurry forms.
Heat the avocado oil in a large skillet or wok over medium-high heat until it begins to shimmer.
Add the seasoned chicken to the hot pan in a single layer and sear until golden brown and cooked through, approximately 5 to 7 minutes.
Remove the chicken from the skillet and set it aside on a plate; immediately add the broccoli, bell peppers, and snap peas to the same pan.
Stir-fry the vegetables for 3 to 4 minutes until they are bright and crisp-tender, adding a splash of water if the pan gets too dry.
Pour the orange sauce mixture over the vegetables and bring it to a gentle simmer.
Whisk the arrowroot slurry once more and pour it into the pan, stirring constantly until the sauce thickens into a glossy glaze.
Return the cooked chicken to the skillet and toss everything together until every piece is beautifully coated in the sauce.
Steam or sauté the cauliflower rice in a separate pan for 2 to 3 minutes until tender but not mushy.
Divide the cauliflower rice into bowls and top with the orange chicken stir-fry, finishing with sliced green onions and sesame seeds.