Slice chicken thinly against the grain. Toss with soy sauce, cornstarch, garlic powder, and white pepper. Rest 10 minutes.
Whisk sweet chili sauce, soy sauce, rice vinegar, honey, sesame oil, garlic, ginger, and cornstarch slurry together. Set aside.
Prep all vegetables before heating the wok.
Heat wok over highest heat. Add 1 tablespoon oil until shimmering and just smoking.
Add chicken in a single layer. Cook 2–3 minutes without moving until golden underneath.
Toss and cook 1–2 minutes until cooked through and caramelized at the edges. Remove and set aside.
Return wok to high heat. Add remaining tablespoon of oil.
Add onion and broccoli. Toss continuously for 2 minutes.
Add bell peppers and sliced garlic. Toss 1–2 minutes until just softening at edges.
Add snap peas and grated ginger. Toss 60 seconds until bright green and crunchy.
Return chicken to the wok. Pour sauce over everything. Toss vigorously 60–90 seconds until glossy, sticky, and coating everything evenly.
Taste and adjust with soy sauce, lime, or extra sweet chili sauce.
Remove from heat immediately. Serve over rice or noodles topped with sesame seeds, spring onions, cilantro, and lime wedges.