Peel the plantains by cutting off the ends and making a lengthwise slit through the skin. Remove the peel and slice the plantains diagonally into 1/2-inch thick pieces.
In a large bowl, toss the plantain slices with salt, ground black pepper, and ground cayenne pepper (if using) until they are evenly coated.
In a large skillet, heat the vegetable oil over medium-high heat until hot. You can test if the oil is ready by dropping a small piece of plantain into the oil. If it sizzles, the oil is ready.
Carefully add the plantain slices to the hot oil in a single layer, making sure not to overcrowd the skillet. You may need to fry them in batches.
Fry the plantains for about 2-3 minutes on each side, or until they are golden brown and crispy.
Use a slotted spoon to remove the fried plantains from the oil and transfer them to a plate lined with paper towels to drain any excess oil.
Enjoy your meal!