Pat dry the chuck roast with paper towels. Set aside.
In a small mixing bowl combine the chili powder, salt, black pepper, cumin, garlic powder, onion powder, oregano, and cayenne pepper.
Season the chuck roast with the seasoning mix. Set aside.
Heat up 2 tablespoons olive oil in a large skillet set over medium heat.
Add the chuck roast to the heated oil and sear on all sides until just browned.
Transfer browned beef to the insert of your slow cooker.
To the slow cooker, add the diced bell peppers, onions, garlic, chipotle peppers, adobo sauce, can of diced tomatoes with chilies, beef broth, and lime juice.
Cover and cook on LOW for 6 to 8 hours, or until meat is very tender and falling apart. The goal for perfectly tender beef is an internal temperature of 205˚F to 215˚F. You’ll know it’s ready when the meat falls apart as you pierce it with a fork.
Remove meat from the slow cooker and transfer it to a cutting board; shred with forks. Set aside.
Using an immersion blender, blend the cooking liquid inside the slow cooker until smooth and thickened.
Toss meat with the cooking liquid.
Taste for salt and pepper and adjust accordingly.
Serve with corn or flour tortillas, if desired, and topped with cheese, onions, lettuce, and sour cream.