Gather all the ingredients.
Shred cabbage using a shredder and transfer to a serving plate.
Take chicken fillets, pat dry with paper towels, sprinkle with salt & pepper and set aside.
In a Teflon sauce pan, add Japanese Sake, Swerve or Monkfruit, Soy Sauce, optional Xanthan Gum and bring to boil. Once boiling, reduce heat to med-low heat and let it cook for 2 minutes while occasionally stirring. Once 2 minutes has passed, remove from heat and set aside. Note - if you opt not to use Xanthan Gum, the teriyaki sauce will be runny.
While waiting for the teriyaki, heat up olive oil in a cast iron pan on high. Once the oil starts to 'smoke', reduce heat to medium and carefully add chicken inside the cast iron pan (take caution as oil may splatter. You may partially cover the pan to reduce splatter as well). Cook until chicken has a nice crust, about 3-4 minutes.
Once crusted, flip and cook for 3-4 more minutes or until done (time will depend on the thickness of chicken thigh, so if you are unsure, either cut to check or use a meat thermometer, center internal temp should be 165F).
Transfer chicken onto a bed of cabbage, pour ~2 tbsp of the teriyaki sauce onto each serving and sprinkle toasted sesame seeds.