Place sliced onion in the bottom of the insert of your slow cooker.
Add coconut milk, garlic, ginger, fish sauce, lime juice, sesame oil, sugar, and spices. Toss to combine.
Add in chicken and mix to coat.
Set on high for 4 hours. When done, shred with two forks.
Serve over white rice or cauliflower rice, garnish, and enjoy.
For Whole30, omit the sugar.