In a medium sized bowl, mix together the soy sauce, hoisin, sugar, garlic, chili garlic sauce, sesame oil, and fish sauce if using. Whisk and add chicken stock.
Add chicken to crock pot or instant pot and pour over sauce.
Slow cook on high for 3-4 hours, low 6-8 hours. Flipping chicken 1/2 way, if possible. Not necessary.
Remove chicken and shred in a bowl with two forks. Return to sauce in Crock Pot.
Add broccoli florets on top of chicken, mix, and cook on high for another 30 minutes.
Serve over rice and enjoy!
Notes
Instant Pot: To use an Instant Pot, set to manual mode and cook on high for 8 minutes and then vent immediately to release pressure. Remove lid and add broccoli put the lid back on to let the broccoli "steam" in the instant pot for a few minutes.