Toss together arepa flour (Pre-cooked corn meal – find at Walmart), cheese, and 1/8 teaspoon salt in a bowl, then stir in water until incorporated.
Let stand until enough water is absorbed for a soft dough to form, 1 to 2 minutes (dough will continue to stiffen).
Form 3 level tablespoons dough into 1 ball and flatten between your palms, gently pressing to form a 1/4-inch-thick patty (2 1/2 to 2 3/4 inches wide), then gently press around side to eliminate cracks. Transfer to a wax-paper-lined surface.
Form more disks with remaining dough in same manner, transferring to wax-paper-lined surface.
Heat a large nonstick or cast-iron skillet over medium, then put some oil to cook arepas in 2 batches, turning over once, until deep golden in patches, 8 to 10 minutes total per batch.