How to Make It
In a bowl, mix the masa harina, water and 1 teaspoon of salt to form a soft dough. Cover with plastic wrap and let stand for 15 minutes.
Meanwhile, in another bowl, toss the cabbage, onion and vinegar. Season with salt.
In a small bowl, combine the pork and cheddar and season with salt and hot sauce. Form the pork filling into 4 compact balls.
Form the dough into 4 balls and cover with plastic wrap. Working with one ball at a time, flatten it on a sheet of plastic wrap to a 7-inch round. Place a pork filling ball in the center of the dough. Bring the dough up to cover the filling. Gently flatten the ball into a 4-inch patty and patch any holes or tears. Repeat with the remaining dough and filling.
In a large skillet, heat 1/4 inch of vegetable oil until shimmering. Add the arepas and fry over high heat, turning once, until golden, crisp and heated through, about 6 minutes. Drain on paper towels and transfer to plates. Using a slotted spoon, mound the cabbage slaw on top of the arepas and serve with jalapeños, cilantro and sour cream.
The uncooked arepas can be stacked between sheets of plastic wrap and refrigerated overnight. Bring the arepas to room temperature before frying.