Heat a nonstick skillet over medium heat and add the ground chicken.
Cook the chicken, breaking it up with a spatula, until no pink remains and it is cooked through, about 6–8 minutes.
Drain any excess fat, transfer the cooked chicken to a mixing bowl, and set aside.
In the same skillet, add the toasted sesame oil and warm over medium-low heat.
Add the grated ginger, diced red bell pepper, and bean sprouts (if using) to the skillet and cook, stirring occasionally, for about 5 minutes until softened.
Add the minced garlic and cook for 1 minute more, stirring so it does not burn.
Return the reserved cooked chicken to the skillet, add the lite soy sauce (or tamari), and stir to combine; cook 1–2 minutes until heated through.
Spoon an even amount of the chicken mixture into each iceberg lettuce leaf, top with sliced scallions, and serve immediately.
