Slow cooker pulled pork or beef

We kept this recipe we found in Family Fun magazine and made it many times.

1 3 to 4 pound pork butt roast or beef brisket
salt and pepper to taste
2 medium onions, sliced
1 16 ounce jar barbecue sauce

Carefully trim the meat of visible fat and season it with salt and pepper.  Place the onions in the bottow of the crock pot slow cooker, then lay the meat on top of them.  You may have to cut the brisket in half and stack the pieces.)  Pour about a half cup of the barbecue sauce over the meat and flip it around to coat it.  Cover and let it cook for 9 to 10 hours on low.  Carefully removed the cooked meat from the crock and pour out the fat and juices, retaining the onions.  For the pork:  Using two forks, shred the meat into stringy chunks, discarding any fat.  Put the meat back in the crock, mix in the remaining barbecue sauce, and let it cook another half hour or so.
For the beef:  Slice the brisket across the grain and place it on a platter, discarding any fat.  Cover it with sauce and let it sit for 10 minutes or so.  Then serve and enjoy!