Pulled Pork Tacos with Pickled Red Onions and Cilantro Pesto

Name: Pulled Pork Tacos with Pickled Red Onions and Cilantro Pesto
Ingredients: 10 lb bone in pork butt; 1/2 c brown sugar, firmly packed; 4 tsp salt; 4 tsp black pepper; 2 tsp cayenne pepper; 2 tsp cinnamon; 2 Tbsp cumin; 2 tsp Sazon adobo seasoning; 2 tsp paprika; 1/4 Tbsp olive oil; 2 c dark beer; 2 c chicken stock; 1/2 red onion, sliced; 3 1/4 c fresh cilantro; 2 c apple cider vinegar; 3 clove garlic, chopped; 1/2 c pumpkin seeds, toasted; 1/4 c water; 2 Tbsp sour cream; 1 Tbsp lime juice; 20 tortillas, corn