Prepare the dough: In a large mixing bowl, combine the masa harina, warm water, and salt. Stir until the mixture forms a dough. If desired, add 1 tablespoon of butter for richness.
Shape the arepas: Divide the dough into 6-8 equal portions. Roll each portion into a ball and flatten it into a thick patty about ½ inch thick.
Cook the arepas: Heat a skillet or cast iron pan over medium heat. Add a little oil if desired. Place each arepa in the pan and cook for 3-4 minutes per side, or until golden brown and crispy.
Add cheese (optional): If you want to stuff your arepas with cheese, make a small slit in the center of each arepa and stuff with your preferred cheese. Return to the skillet for an additional minute to melt the cheese.
