Put milk and water in a small saucepan over medium-low heat until steam rises.
Remove from heat and stir into cornmeal mixture until a thick batter is formed.
Season batter to taste and add more cornmeal if needed.
Let batter rest until it thickens into a soft dough, about 15 minutes.
Gently form 3- to 4-inch balls from mixture and flatten with palm of your hand to a 1/2-inch-thick disk.
Heat olive oil in a large skillet and cook arepas, working in batches, until golden brown, about 3 minutes on each side.
Serve and enjoy!