Prepare the Dough:

1. Mix the Masa: In a large bowl, combine masa harina, warm water, and salt. Knead until a smooth, pliable dough forms. If the dough feels dry, add a tablespoon of water at a time until the desired consistency is reached. Cover with a damp cloth to prevent drying.

Prepare the Filling:

2. Combine Beans and Cheese: In a separate bowl, mix the refried beans and shredded cheese until evenly combined.

Assemble the Pupusas:

3. Divide the Dough: Portion the dough into 12 equal balls, about the size of a golf ball.
4. Flatten and Fill: Take one dough ball, flatten it slightly in your hand, and create a small well in the center. Add about 1 tablespoon of the bean and cheese mixture. Carefully fold the edges of the dough over the filling, sealing it completely. Flatten the filled ball into a disc about 4-5 inches in diameter.
5. Repeat: Continue this process with the remaining dough and filling.

Cook the Pupusas:

6. Heat the Griddle: Preheat a nonstick griddle or skillet over medium heat.
7. Cook the Pupusas: Place the pupusas on the hot griddle and cook for 2-3 minutes per side, or until golden brown with slightly charred spots. Flip gently and repeat on the other side.

Serve Immediately:

8. Plate and Enjoy: Serve hot with curtido and salsa roja on the side for dipping or topping.