In a large bowl, combine the pork pieces, salt, ground black pepper, ground cumin, and minced garlic. Mix well to ensure the pork is evenly seasoned.
In a large pot or deep skillet, add the seasoned pork pieces and chopped onion.
Pour in the water and bring to a boil over medium-high heat.
Reduce the heat to medium and let the pork simmer until the water has evaporated and the pork starts to render its fat, about 30-40 minutes.
Once the water has evaporated and the pork has started to brown in its own fat, add the vegetable oil or lard to the pot.
Continue to cook the pork over medium heat, stirring occasionally, until the pork is crispy and golden brown on all sides, about 15-20 minutes.
Add the white vinegar during the last few minutes of frying to enhance the flavor and crispiness.
Remove the pork pieces from the oil and drain them on paper towels to remove any excess oil.
Transfer the chicharrón to a serving dish.
Garnish with freshly chopped cilantro and serve with lime wedges on the side.
Chicharrón can be enjoyed on its own as a snack or appetizer.
It can also be served with traditional Bolivian accompaniments such as boiled potatoes, corn on the cob, or llajwa (a spicy tomato sauce).
Enjoy your meal!