This stew has a simple list of ingredients, but plenty of great flavor thanks to flank steak, a cut that’s known for it’s excellent meaty flavor. The flank is also known for it’s long grainy, and sometimes tough texture. In this stew the texture is a great asset—the meat shreds apart into tasty strips after it’s cooked in the slow cooker.
Combine broth, vinegar, celery, onion, bell pepper, garlic, cumin, salt and pepper in a 6-quart slow cooker. Add beef, submerging it by tucking the vegetables under, over and between the pieces.
Put the lid on and cook on low until the meat is fork-tender, about 8 hours.
Transfer the meat to a cutting board; let stand for 10 minutes. Shred the meat with 2 forks and return it to the slow cooker. Stir in cilantro. Garnish with jalapeno and serve warm tortillas on the side.
Cover and refrigerate for up to 3 days or freeze for up to 1 month.