Make the arepa dough: In a bowl, combine the pre-cooked cornmeal and salt. Gradually add warm water, stirring constantly to avoid lumps. Knead the dough for 3-4 minutes until smooth and slightly sticky. Rest for 5-10 minutes and optionally add butter or oil for a softer dough.

1. Shape the arepas: Divide the dough into 6-8 equal portions and roll into balls. Flatten each ball into a disc about 1/2 inch thick. Smooth the edges with wet hands if necessary.
2. Cook the arepas: Heat a griddle or skillet over medium heat and lightly oil it. Cook the arepas for 5-7 minutes on each side until golden and crispy. Optionally, finish cooking in the oven at 350°F (175°C) for 10-12 minutes.
3. Cut and stuff the arepas: Once cooked, slice the arepas horizontally, creating a pocket. Fill with your choice of fillings like carne mechada, cheese, avocado, black beans, or chicken.
4. Serve: Serve your arepas hot with salsa, avocado, or a cold drink like freshly made fruit juice or beer.