In a large bowl, whisk together the cornmeal, slat, cotija cheese and 2 cups of shredded cheese.
Stir in the water and melted butter to form a soft dough. It should feel like a soft homemade playdough consistency.
Cover the bowl with a kitchen towel and allow it to sit for 10 minutes.
Knead the dough for a few minutes until it is smooth and soft. It should hold its shape, but be easily worked.
Divide the dough into 16 equal balls.
Pat each ball of dough into a 5 inch circle that is about ¼” thick.
Place a few tablespoons of shredded cheese in the middle of the patty.
Fold and wrap the dough around the cheese, ensuring all the cheese is well sealed inside.
Pat the dough into a patty that is about 3 inches wide and a ½” thick.
Repeat with remaining balls of dough.
Heat a 12” cast iron skillet over medium high heat. If you have an electric griddle, this works well, too, because you can cook more than 1 at a time!
When the skillet is hot, place a small pad of butter on the skillet and spread it around to coat the surface.
Place the arepas on the skillet and cook for 5 minutes, until crispy and golden.
Flip and cook on the second side for 5 minutes.
Transfer to a wire rack to cool while you continue cooking the rest.
Notes
Leftover fried arepas can be stored in a sealed container in the fridge for up to 3 or 4 days.To reheat leftover arepas, you can put them in a 350F oven or toaster oven for about 10 minutes. You can also reheat them in the microwave, but you lose a little of the crispy and tender texture this way.