In a bowl, combine the chili powder, cumin, oregano, and paprika; season to taste with salt and pepper.
1 tbsp. chili powder, 1 tbsp. ground cumin, 2 tsp. dried oregano, 1 tsp. paprika, Sea salt and freshly ground black pepper
Rub the pork shoulder evenly with the spice mixture.
4 to 5 lbs. pork shoulder
Place the pork in a slow cooker and top with the garlic, onion, and jalapeno.
1 onion, 4 garlic cloves, 1 jalapeño
In another bowl, whisk together the tomato paste, orange juice, and lime juice.
2 tbsp. tomato paste, ¼ cup orange juice, ¼ cup fresh lime juice
Pour the sauce over the pork, cover, and cook on low for 6 to 8 hours.
Once the pork is cooked through, shred the pork using a fork and place it back in the slow cooker mixing it with all the juices from the cooking process.
Grill the shredded pork on a preheated grill, or in the oven at 475 F for 10 to 12 minutes, to get a nice charred texture.