In a large mixing bowl, combine the masa harina and salt. Gradually add the warm water while mixing with your hands. Knead the dough until it is soft, pliable, and slightly sticky, but not wet. Cover with a damp cloth to prevent drying while preparing the filling.

Prepare the filling by mixing the shredded cheese, refried beans, and optional pork in a separate bowl. Ensure the ingredients are evenly distributed. For added depth, sprinkle cumin over the mixture and blend well.

Divide the dough into 8 equal portions, rolling each into a smooth ball. Flatten each ball slightly to form a disc about 3 inches in diameter. Keep the unused dough covered as you work.

Take one dough disc and press a small indentation in the centre. Add about 1 tablespoon of the filling mixture. Carefully fold the edges of the dough over the filling, sealing it completely. Gently flatten the ball between your palms to form a disc, approximately 4–5 inches wide. Repeat with the remaining dough and filling.

Preheat a griddle or large non-stick skillet over medium heat. Lightly grease it with a small amount of oil or cooking spray. Avoid over oiling to maintain the traditional crisp surface of the pupusa.

Cook the pupusas on the preheated griddle for 3–4 minutes per side, or until golden brown with light char marks. Press gently with a spatula to ensure even cooking, but avoid breaking the surface.

Once cooked, transfer the pupusas to a plate and cover them loosely with foil to keep warm. Repeat the process until all pupusas are cooked. If any filling leaks during cooking, consider it a badge of authenticity!

Serve the pupusas hot, accompanied by curtido and salsa roja. For presentation, place the pupusas on a platter with small bowls of curtido and salsa on the side. Encourage diners to layer the slaw and sauce atop each pupusa for the best flavour experience.