Season pork with brown sugar and all the spices. Toss in a bowl to fully coat everything.
In the pressure cooker, sear off all the pork until it has developed a nice crust. You may have to do this in batches.
Slice the limes, lemons, and onions in half. In a food processor, blend the peeled onions with the juices from the citrus. Add in a splash of SUNNYD as well.
Pour the blended mixture over the pork in the pressure cooker.
Pour over the water to create steam. Pressure cook for 1 hour!
Release the steam, and remove the pork from the pressure cooker.
In a bowl, shred the pork with your hands or a fork! Place aside.
Toast the brioche bun in melted butter until golden brown.
To assemble, place pulled pork onto the bun, adding coleslaw is optional but recommended!!