Make the dough: In a large bowl, mix cornmeal and salt. Gradually add warm water while mixing with your hands until a soft, pliable dough forms.

Rest the dough: Cover with a damp cloth and let rest for 5 minutes. The dough should be moist but not sticky. Adjust with more water or cornmeal if needed.

Shape the arepas: Divide dough into 8 equal portions. Roll into balls, then flatten to 1/2-inch thick patties (about 3-4 inches diameter). Smooth any cracks.

Cook first side: Heat oil in a non-stick skillet over medium heat. Cook arepas for 5-7 minutes until golden brown spots appear.

Flip and cook: Turn arepas over and cook another 5-7 minutes. They should sound hollow when tapped.

Finish cooking: Transfer to a 350°F oven for 10 minutes to ensure they cook through completely.

Serve: Slice open while warm and fill with your choice of cheese, shredded meat, beans, or avocado. Spread butter on the inside if desired.