Preheat the oven to 200 degrees F (93 degrees C).
In a small bowl, mix the Brown Sugar (2 tablespoon), Salt (1 teaspoon), Ground Black Pepper (1 teaspoon), Lime Juice (4 tablespoon), and Orange Juice (4 tablespoon) with the Boneless Pork Shoulder (2 pound). Cover and marinate overnight, or up to 24 hours.
Discard marinade and place the pork shoulder in the dutch oven.
Add the Dried Pasilla Chile Pepper (1), Garlic (4 clove), Yellow Onion (1), Bay Leaf (2), Cinnamon Stick (1), Ground Annatto (2 teaspoon), Dried Oregano (1 teaspoon), Salt (1 teaspoon), Black Peppercorns (1 teaspoon), Ground Coriander (1 teaspoon), Vegetable Broth (1/4 cup), Lime Juice (2 tablespoon), and Orange Juice (2 tablespoon) to the dutch oven. Toss to combine.
Slow-cook in the oven for 7-8 hours at 200 degrees F (93 degrees C), or until meat is tender.
Remove Pork shoulder from the dutch oven. Shred pork shoulder using a fork or by hand.
Strain cooking liquid through a sieve to remove any solids, but reserve the liquid.
Add 2/3 cup cooking liquid over meat. Toss to combine.
In batches, transfer shredded meat to a non-stick frying pan over high heat. Without touching the meat, cook until the underside is browned, about 5 minutes. Toss to continue cooking, until some edges start to crisp up, about another 5 minutes, toss occasionally.
Turn off the heat, add 4 tbsp more cooking liquid to the pan, mix evenly.
In a bowl, drizzle juice from the Lime (1) over the Red Onion (1) to make a quick pickle.
Serve carnitas on Yellow Corn Tortilla (12), top with Salsa Verde (to taste), pickled onions, and Fresh Cilantro (1 bunch).