Cut the beef into 2 inch pieces, season generously with steak seasoning,garlic powder, and oregano. Drizzle with olive oil, set aside or better yet, marinate overnight.
Add 3 to 4 tablespoons of olive to a sklillet and heat to medium/high heat. Sear the beef in batches and transfer to the crockpot. Once all beef has been browned nicely, add the add the beer, broth and Worcestershire sauce to the crockpot .
Cover with lid and cook on high for 5-6 hours
Preheat a skillet to medium heat. Add the chile de arbol and toast, turning often. It should only take a 2 minutes, they will become aromatic and brown in some spots. Transfer onto plate.
Remove stems from chiles, and combine with remaining salsa ingredients in blender. Blend until smooth taste for salt. The flavor on this salsa improves the longer it sets.
When ready, remove beef from pot and shred with two forks. Take some of the broth left in pot and pour over beef to moisten. Serve right away with warm tortillas for tacos. Garnish with chopped cilantro,onion, salsa and guacamole.
Notes
Tips~ When choosing a roast, look for one that has some marbelization. The fat will yield a more moist shredded beef.