Step 1

Preheat a 5-to-6-quart slow cooker. Season steak generously with salt and pepper. In a large skillet, heat 1 tablespoon oil over high. Add steak and cook until browned on both sides, about 8 minutes. Transfer to slow cooker.

Step 2

Add remaining 1 tablespoon oil to skillet. Add onions, bell pepper, garlic, jalapeno, and cumin seeds; season with salt and pepper and cook until vegetables are tender, about 5 minutes. Stir in tomato paste; cook 2 minutes more. Add tomatoes and bring to a boil. Pour mixture over steak in slow cooker; cover and cook on high until very tender, 5 hours (or on low 10 hours).

Step 3

Transfer steak to a platter; cut in half crosswise. Using two forks, shred meat. Transfer sauce to skillet; cook over high heat until slightly thickened, about 10 minutes. Stir in shredded meat, olives, and capers with brine; cook just until heated through, 2 minutes more. Top with cilantro and serve, with rice and plantain chips.