Add all the marinade ingredients into a blender.
Blend until smooth.
Chop up the pork into pieces.
The size of the pieces do no matter since the meat will be shredded later.
In a container, pour some of the marinade over the pork.
Individually marinate the pieces of pork.
Do not add all the sauce over the pork. Use only what is necessary.
Cover the pork, and let sit in the fridge overnight.Minimum 4 hours.
When ready, heat the banana leaves over a hot griddle or gas stove.
Move the banana leaf quickly and carefully over the flame.
As soon as it turns dark green, it is ready.
Wash the banana leaves.
Place one of the banana leaves into the slow cooker lengthwise.
Place another banana leaf, over the other leaf criss cross.
Some of the banana leaves will overflow out of the slow cooker.
Add the marinated pork into the banana leaves.
Cover the meat with the overflowing banana leaves, wrapping the pork.
Add the water around the banana leaves. Not directly into the pork wrapping.
Set the slow cooker to low for 8 hours, or high for 6 hours.
Once it's ready, remove the lid to the slow cooker.
Open up the banana leaves.
Carefully remove the pork to a separate container and shred the meat.
Discard the banana leaves.
Serve as tacos on corn tortillas and top with pickled red onions.