Combine seasoning blend: Put all the ingredients for the spice mix in a small bowl – paprika, cumin, oregano, chili powder, onion powder, garlic powder, and coriander. Add 1 1/4 teaspoon salt and 1/2 teaspoon black pepper. Stir well to combine.
Season beef: Put the beef on a clean surface. Sprinkle two tablespoons of the seasoning blend over the beef. Work the spices into the meat with your hands.
Sear beef: In a Dutch oven or large heavy-bottomed pot, heat 1 1/2 tablespoons oil over medium-high heat. Add meat (in batches if necessary) and brown on all sides, about 8 minutes. Add more oil if necessary if browning meat in batches. Remove to a plate.
Sauté vegetables: As soon as the pot is now empty, reduce the heat to medium and add the remaining 1 1/2 tablespoons of oil, followed by the onions. Season the onions with a pinch of pepper and a pinch of salt. Sauté, stirring occasionally, for about 3 minutes. Stir in garlic and the remaining seasoning blend. Cook, stirring constantly, for about 30 seconds before it becomes fragrant. Then add the tomato paste and chopped chipotles. Stir constantly until the paste is caramelized, about 1-2 minutes.
Deglaze + add beef: Deglaze the pan with lime juice. Cook, scraping up any browned bits at the bottom, then add the adobo sauce, the stock, the Picante sauce, and the bay leaf. Mix well, and then add the seared beef, along with any accumulated juices, to the pot.
Cover + cook: Bring the contents to a simmer. Cover the pot and reduce the heat to low. Simmer covered for 3 – 3 1/2 hours, or until the meat becomes tender and falls apart. You should stir the beef every hour to achieve the best results.
Shred beef: Turn off the heat in the pot. Remove the bay leaf with tongs and discard it. Shred the beef with two forks (you can also remove the beef to a cutting board, shred it, and return it to the pot.)
Gently simmer to warm: Reduce the heat to low and gently simmer the meat for about 10-15 minutes.
Serve: To serve, place beef in a serving dish and top with cilantro. Serve with lime wedges.
For tacos: Add shredded cheese to warmed corn tortillas and top with shredded beef; garnish with chopped veggies, pico de gallo, fresh cilantro, guacamole, or sour cream.