Steps:

• Rub the pork with salt and pepper, and then set aside while you prepare the remaining ingredients. (See notes below if you plan to sear the pork first).
• Heat oil in a wide skillet over medium heat. Add the onions and garlic then cook, occasionally stirring, until they are sweet and browned around the edges. Stir in the tomato paste, chili powder, and cumin. Cook, stirring until the tomato paste turns from bright red to orange in color; about 3 minutes. Add the water, apple cider vinegar, and fish sauce and cook for about 1 minute, scraping up the browned bits on the bottom of the pan.
• Rest the seasoned pork in the bottom of a slow cooker then pour the onion and spice mixture on top. Wiggle the pork around the bottom of the slow cooker so that some of the onion and spice mixture slides underneath. Cover with lid and cook until the pork can be easily shredded; LOW for 6 to 8 hours or HIGH for 4 to 6.
• Turn off the slow cooker and transfer the pork to a cutting board. If the pork has a bone in it, remove and discard it. Use two forks to shred the meat, discarding any connective tissue, and large clumps of fat.
• Remove the cooking liquid and skim most of the fat from its surface. Discard the fat then set the cooking liquid aside.
• If using barbecue sauce, add it to the slow cooker and stir in the shredded pork. For even more flavor, add back some of the reserved cooking liquid. If you’re not using barbecue sauce, add the shredded pork and the cooking liquid back to the slow cooker. Taste and season with salt, additional vinegar, or hot sauce as needed.

Steps:

• Rub the pork with salt and pepper, and then set aside while you prepare the remaining ingredients. (See notes below if you plan to sear the pork first).
• Heat oil in a wide skillet over medium heat. Add the onions and garlic then cook, occasionally stirring, until they are sweet and browned around the edges. Stir in the tomato paste, chili powder, and cumin. Cook, stirring until the tomato paste turns from bright red to orange in color; about 3 minutes. Add the water, apple cider vinegar, and fish sauce and cook for about 1 minute, scraping up the browned bits on the bottom of the pan.
• Rest the seasoned pork in the bottom of a slow cooker then pour the onion and spice mixture on top. Wiggle the pork around the bottom of the slow cooker so that some of the onion and spice mixture slides underneath. Cover with lid and cook until the pork can be easily shredded; LOW for 6 to 8 hours or HIGH for 4 to 6.
• Turn off the slow cooker and transfer the pork to a cutting board. If the pork has a bone in it, remove and discard it. Use two forks to shred the meat, discarding any connective tissue, and large clumps of fat.
• Remove the cooking liquid and skim most of the fat from its surface. Discard the fat then set the cooking liquid aside.
• If using barbecue sauce, add it to the slow cooker and stir in the shredded pork. For even more flavor, add back some of the reserved cooking liquid. If you’re not using barbecue sauce, add the shredded pork and the cooking liquid back to the slow cooker. Taste and season with salt, additional vinegar, or hot sauce as needed.