In a mixing bowl, combine the masa harina and salt.

Gradually add the warm water and mix until a soft dough forms.

Cover the dough with plastic wrap or a damp cloth and let it rest for about 15 minutes.

Divide the dough into 8 equal portions and roll each into a ball.

Using your hands or a rolling pin, flatten each ball into a disc about ½ inch thick.

Place a tablespoon of cheese and beans in the center of each disc. If using pork, add that too.

Carefully fold the edges of the disc over the filling, pinching them to seal.

Heat a cast-iron skillet or griddle over medium heat.

Cook each papusa for about 3-4 minutes on each side until golden brown and crispy.

Remove the papusas from the skillet and serve warm with curtido and salsa roja.