Velvet the chicken Slice chicken breast thin against the grain about quarter inch thick. In a bowl, combine cornstarch, egg white, baking soda, and one tablespoon soy sauce. Add chicken and toss until every piece is evenly coated. Set aside for 15 to 30 minutes. Do not skip this step - it is what gives chicken stir fry its silky restaurant texture.
Make the sauce Whisk together soy sauce, oyster sauce, honey, rice vinegar, sesame oil, cornstarch, and white pepper in a small bowl until smooth and the cornstarch is fully dissolved. Taste and adjust more honey for sweetness, more soy sauce for saltiness. Set next to the stove.
Prep all vegetables Wash and completely dry all vegetables. Cut broccoli into bite sized florets, slice bell pepper thin, remove strings from snap peas, slice mushrooms. Mince garlic and grate ginger. Everything must be ready before cooking starts chicken stir fry moves too fast to prep mid-cook.
Cook the chicken Heat one tablespoon of avocado oil in a large skillet or wok over high heat until shimmering and almost smoking. Add velveted chicken in a single layer do not crowd. Cook undisturbed for 90 seconds until white on the bottom, then toss for another 60 seconds until just cooked through. Remove to a clean plate.
Stir fry the vegetables Add remaining tablespoon of avocado oil to the same pan over high heat. Add broccoli and mushrooms first they need more time. Toss constantly for 2 minutes. Add bell pepper and snap peas. Toss for another 90 seconds. Vegetables should be crisp tender with slight char at the edges.
Add garlic and ginger Push vegetables to the side of the pan. Add garlic and ginger to the center. Toss for 30 seconds until fragrant. Do not let them sit still or they will burn.
Return chicken and add sauceReturn cooked chicken to the pan. Give the sauce a quick whisk and pour over everything. Toss constantly over high heat for 30 to 45 seconds until the sauce thickens, turns glossy, and coats every piece of chicken and vegetable.
ServeRemove from heat immediately. Transfer chicken stir fry to a serving plate or directly over steamed jasmine rice. Garnish with sliced green onions and sesame seeds. Serve immediately while sauce is at peak glossiness and vegetables are still crisp.