Cut the pork into chunks. Season with salt and pepper. Add cooking oil to a large stockpot. When hot, add the pork chunks and brown on all sides. When done, add water to almost cover the meat. Then add onion, celery, and bay leaf. Cover and cook until fork tender.
When done, remove the pork from the pot and shred it. Put the shredded meat in a bowl. Add half the BBQ sauce. Mix it well.
Shred the cabbage. Add it to a bowl with the cilantro, mayonnaise, apple cider vinegar, and sugar. Mix it well.
Using one egg roll, add a small amount – around 2 tbsp – of pulled pork and around 1 tbsp of coleslaw.
Fold in the left and right sides of the egg roll so they overlap in the middle. Fold the edge closest to you over the filling. Then roll away from you. Dab water on the loose end and press it against the eggroll, to ensure it doesn’t come loose.
Set up two wire racks with paper towels underneath to catch the oil. Heat 2 inches of vegetable oil to 375º. It’s important to maintain this heat so the rolls don’t soak up excess oil. Working in batches, fry the egg rolls until golden brown, around 3 to 4 minutes. Transfer the egg rolls to the wire racks to cool.
Serve with the remaining BBQ sauce or a combination of BBQ sauce and mayonnaise.