For the patties: Prepare a grill for medium-high heat or prepare a smoker to 225 degrees F.
Heat the vegetable oil in a large skillet over medium-high heat. Add the celery, bell pepper and onion and saute until transparent and soft. Set aside to cool completely.
While the vegetables are cooling, put the ground pork in a large bowl. Add the sauteed vegetables, BBQ sauce, hot sauce, Worcestershire sauce, salt, garlic powder, onion powder, paprika and black pepper. Mix together with your hands until well-blended. Shape the meat into five 8-ounce patties.
Grill or smoke the patties until the internal temperature on an instant-read thermometer registers 165 degrees F, about 4 minutes per side on a grill and 50 minutes in a smoker.
For the fried onions: Heat a deep fryer with vegetable oil.
Soak the julienned onion in a bowl with the buttermilk for 5 minutes. Combine the flour, cornmeal and Cajun seasoning in a shallow bowl. Remove the onion from the buttermilk (letting the excess drip off) and dredge in the seasoned flour. Working in batches, fry in the hot oil until crispy, about 2 minutes. Set aside.
For the coleslaw: Combine the green and red cabbage, carrots and coleslaw dressing in a large bowl and toss well to coat.
To assemble: Place some coleslaw in the bottom of each bun. Top with a patty, some BBQ sauce and fried onions. Add the bun tops and enjoy.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.