How to Make It
Combine chipotle chiles, adobo sauce, oil, honey, cumin, salt, and black pepper in a small bowl. Rub mixture into brisket, covering all sides.
Combine onion and bell peppers in a 5- to 6-quart slow cooker coated with cooking spray. Pour beef stock over onion and pepper mixture. Nestle brisket into mixture. Cover and cook on low until brisket is very tender, about 8 hours.
Remove brisket from slow cooker, and shred with 2 forks. Return shredded meat to slow cooker, and toss with vegetables before serving.