Place the flank steak in a large pot of water with a pinch of salt and bring to a boil; simmer for about 1 hour until the beef is very tender.

Remove the beef from the pot, let it cool slightly, and shred it into fine strands using two forks or your fingers.

In a large skillet, heat 1 tablespoon of vegetable oil over medium heat and sauté the chopped onion and red bell pepper until soft, about 5-7 minutes.

Stir in the minced garlic, ground cumin, and black pepper, cooking for another minute until fragrant.

Add the shredded beef and crushed tomatoes to the skillet, stirring to combine well, and simmer for 10-15 minutes until the sauce thickens and coats the meat.

While the meat simmers, prepare the dough by mixing the cornmeal, warm water, and 1 teaspoon of salt in a bowl until smooth and free of lumps.

Let the dough rest for 5 minutes, then divide it into 4 equal portions and form them into discs about 1/2 inch thick.

Heat the remaining 1 tablespoon of oil in a non-stick pan or griddle over medium heat.

Cook the arepas for about 5-7 minutes on each side until they form a golden, crispy crust and sound hollow when tapped.

Remove the arepas from the heat, slice them open horizontally (leaving the back edge attached), and stuff generously with the warm beef mixture and shredded cheese before serving.