Start by dicing the cucumber, chopping the onion, and finely slicing the jalapeños. Add them to a large bowl along with the coleslaw mix and purple cabbage. Toss in the cilantro and Thai basil for a fresh herbal base.
In a separate bowl, whisk together sesame oil, orange juice, lime juice and zest, lemon juice, soy sauce, and spices. Mix until everything is well combined and slightly emulsified. The citrus and sesame oil create a beautifully balanced dressing.
Pour the dressing over the vegetable mixture. Toss everything thoroughly so the veggies are evenly coated. This step ensures every bite is flavorful and well-seasoned.
Sprinkle sesame seeds over the slaw for added crunch and nuttiness. Give it one final toss to distribute the seeds evenly. This small step adds a nice texture contrast.
You can serve the slaw immediately or let it chill for 20–30 minutes. Chilling allows the flavors to blend together even better. If making ahead, keep dressing separate until serving for best texture.