Step 1

Stir together the brown sugar, chile powder, paprika, garlic powder, salt, black pepper and cayenne in a small bowl. Rub the mixture all over the pork shoulder. Wrap the pork in plastic wrap and refrigerate for several hours or preferably overnight.

Step 2

Preheat the oven to 300 degrees F.

Step 3

Place the pork in a large pot on a bed of the onion halves. Roast until fork-tender and falling apart, about 7 hours. Remove the pork from the pot and set it on a cutting board. Slice some of the onion.

Step 4

Place the pot on the stove over medium-high heat and add 1/2 to 1 cup of hot water. Scrape the pan to loosen up the bits and cook for 5 minutes to reduce. Pour in the barbecue sauce and stir to heat.

Step 5

Shred the meat with two forks, add the sliced onions to the pork and then toss in the barbecue sauce until it's coated to your liking! Serve on hamburger rolls.