Add all the meat ingredients to pressure cooker liner or slow cooker crock.
For Pressure Cooker (Instant Pot): Cook on HIGH pressure for 45 minutes. Release pressure naturally.For Slow Cooker (Crock Pot): Cook on LOW for 8 to 10 hours.
Remove the beef from the cooker and shred using two forks; set aside.
Pour the juices from the liner into a saucepan (or use the pressure cooker's saute function). Allow to boil on high heat, stirring occasionally, until reduced by about half.
Put the beef and the sauce back into the cooker and mix together.
In a glass bowl or a large plastic zip bag, mix together all of the slaw ingredients.