In a small blender jar, combine olive oil, sesame oil, vinegar, sugar, garlic powder, mayo, and salt. Blend until smooth and creamy, about 35 seconds. Stir in sesame seeds. Refrigerate until ready to use.
In a large bowl, combine both cabbages, carrot, chicken, and green onions. If storing for later, keep the dressing separate (see notes). When ready to serve, drizzle with dressing to taste (you likely won’t need it all) and toss until evenly coated, adding more dressing if desired.
Divide onto plates. Top with chow mein noodles (as many as you like) and serve immediately.
Notes
Storage: Once dressed, the salad is best enjoyed right away. For longer storage, keep the salad and dressing in separate containers. Store both in the fridge for 3–4 days. Add chow mein noodles just before serving so they stay crunchy.