Cut up the onions and place them in the bottom of the slow cooker.
Season the pork roast with Kosher salt and pepper. Place the pork on top of onions, fatty side down.
In a separate bowl, mix the olive oil, paprika, chili powder, cayenne, oregano, brown sugar, and garlic until they make a wet paste, then slather that on top of the roast.
Add bay leaf and cook on low for 8-9 hours.
Remove bay leaf, bone, and large pieces of fat, and move the meat and onions to a separate pan to shred.
Shred meat and serve as desired.
Notes
If you want to get super easy-peasy when making pulled pork for sandwiches, simply throw your pork in the slow cooker with a bottle of BBQ sauce and maybe a couple of sliced onions. Here I decided instead to season up this roast to be more versatile — this way everyone can just add their own BBQ sauce to taste when making sandwiches, and we can also use the meat in tacos or burrito bowls.