n a medium to large mixing bowl, add the corn flour first, and then slowly add the water until you form a soft dough that sticks together and can be formed.
Let the flour sit about 5 minutes to fully absorb the water.
Add the shreded / crumbled cheeses and mix well. Test your dough and adjust if it is too dry or two wet (notes below)
Take handfulls of dough and form them into 1cm thick disks. Size is up to you. I like to make them small, around 3-4 inches in diameter.
Heat a large skillet over medium heat and melt the butter
Add the arepa disks and cook until lightly golden on each side, about 3-5 minutes.
Remove the arepas and carefully use a knife to split them down the middle length wise 3/4 of the way
Stuff the apreas with the slices of cheese. If they are too large, you can split the sices
Return the arepas to the pan cook until cheese is melted, flipping as necessary to avoid over-cooking the arepas
Enjoy!