Cook chicken breast halves, shred them, and set aside.
Toast sesame seeds in a small pan over medium heat.
In a small bowl, whisk together vegetable oil, rice vinegar, brown sugar, sesame oil (optional), and soy sauce.
In a large bowl, combine chopped lettuce, shredded chicken, green onions, and toasted sesame seeds.
Cook rice noodles according to package instructions, drain, and add to the salad.
Drizzle the dressing over the salad, tossing everything to combine.
Serve immediately and enjoy the crunch and flavors!