- 1 tablespoon avocado oil
- 2 pounds beef sirloin tip roast
- 1 (28 ounce) can fire-roasted diced tomatoes, drained
- 1 cup beef broth
- 2 onions, sliced
- 3 bell peppers, seeded and sliced into strips
- 1 (6 ounce) can tomato paste
- 2 tablespoons minced garlic
- 1 tablespoon olive oil
- 1 tablespoon red wine vinegar
- 1 teaspoon ground cumin
- 1 teaspoon salt
- 1/4 cup chopped fresh cilantro
- Heat avocado oil in a large skillet over medium-high heat; cook beef roast in the hot oil until browned, about 4 minutes per side. Transfer roast to a slow cooker. Pour tomatoes and beef broth over roast; add onions and bell peppers.
- Mix tomato paste, garlic, olive oil, vinegar, cumin, and salt together in a bowl; pour over onions and bell peppers.
- Cook on High for 1 hour. Decrease heat to Low and cook until beef is tender enough to shred, about 8 hours.
- Remove beef from slow cooker and shred on a work surface using 2 forks. Return shredded beef to slow cooker; add cilantro and stir.
- Cook on Low for 1 hour more.