Pat the pork butt until dry.
Using a a trimming knife, trim any exterior loose pieces of fat. If your pro butt has a fat cap, leave it intact for now. Using a boning knife, make a fut between the fat cap and the meat to make a small “pocket”. If your meat doesn't have a fat capo, that's ok. Make sure you create a pocket large enough to season the meat entirely. The fat cap will keep in all the delicious flavors of the seasoning.
On the rest of the meat, make similar pockets with a knife and insert the garlic slices.
Combine the ingredients for the dry rub and rub all over the pork butt making sure to season under the fat cap like mentioned before.
Place the seasoned pork butt in a slow cooker with fat cap facing up (if it has a fat cap). Add the onion, jalapeño, bay leaf, and fresh squeezed orange juice.
Cook on high for 6. The meat should be tender enough to fall apart at the touch of a fork. Remove the pork butt (reserving liquid) from the slow cooker and allow to cool for a couple of minutes. Using two forks shred the pork.
Keep the juices in the slow cooker if using the below oven method. Now you can either continue on to the next steps & serve right away or store and refrigerate until ready.
Oven Method: Place oven rack 3 inches from top and set the oven to broil. use lard to grease a sheet pan liberally. Spread shredded pork in a single layer. Place pork under broiler 5-6 minutes or until pork is slightly crispy, not dry. (Caution: Oil may smoke due to high heat.)
Remove pan from oven and pour reserved liquid over pork until it sits in the bottom the tray. Don't over pour. Stir and serve immediately.