In a bowl, mix lime juice, minced garlic, olive oil, ground cumin, salt, and black pepper. Add the sirloin steak and coat it well. Let it marinate for at least 30 minutes.

Grill the Steak

Preheat the grill to medium-high heat. Grill the marinated sirloin for about 5-7 minutes per side or until desired doneness. Remove from grill and let it rest for a few minutes before slicing thinly.

Prepare Crispy Onions

Thinly slice the onion and soak in cold water for 10 minutes. Drain and pat dry. Heat vegetable oil in a pan, and fry the onions until golden and crispy. Remove and drain on paper towels.

Prepare the Plantain Fufú

Cook the Plantains

Peel the green plantains and cut them into chunks. Boil in salted water until soft, about 20 minutes.

Mash the Plantains

Drain the plantains and mash them until smooth. You can add a little water if necessary to achieve a creamy consistency.

Prepare the Black Beans

Cook the Black Beans

In a pot, heat olive oil and sauté chopped onion and minced garlic until soft. Add canned black beans (with liquid), cumin, and salt. Simmer for about 10 minutes, stirring occasionally.