Heat 2 cups vegetable oil in a large, deep skillet or deep fryer to 350 degrees F. Place plantain halves in the oil and cook 1 to 2 minutes, until they float. Remove from oil and drain on paper towels.
Place plantain halves between 2 cutting boards. Press to flatten. Place the flattened plantains back in the oil and cook for 2-3 minutes, until golden brown. Drain on paper towels.
Heat 2 tablespoons of oil in a large skillet. Add the garlic, skirt steak, onion, cumin and oregano. Cook, stirring frequently, until steak is cooked through.
To serve, spread mayonnaise on one of the plantain slices. Top with cheese, steak and onion mixture, lettuce, and tomato. Place the other plantain half on top to form a sandwich. Cut in half and serve!
