Start by placing water in a microwave safe bowl and microwave for about 30-45 seconds until water is warm.
Add butter to water and mix until all butter is melted. Then add salt and mix until dissolved.
Place Cornmeal in a large bowl. Add 1 cup of Cotija cheese, 2 cups of the Monterey Jack cheese and mix.
Add wet ingredients to dry ingredients and mix until dough forms. ( I ended up kneaded dough on a wooden cutting board a few times until dough fully came together. If it is too dry when first mixing this is when you will add your additional 1/4 cup of water.)
Wet hands with water and form dough balls. Then form dough into little cups in the palm of your hand. Fill with cheese and fully close. (This is important! You don't want any cheese to escape when it is being cooked. If there are any cracks use some water to seal them up.) Flatten dough into nice discs and set aside. Repeat until all dough and cheese is used up. Depending on how big you make your Arepas you should be able to make about 12.
Heat a large skillet over medium heat. Butter the skillet and cook Arepas for 5-6 minutes of each side until golden brown. (Be sure to butter your skillet in between each batch.)
Sprinkle with flaky salt and enjoy!