Add room temperature water and masa to medium-sized bowl. Begin to mix it by hand to form a dough. Once a soft dough is formed, cover it with a piece of plastic wrap and allow it to sit for 30 minutes before forming pupusas.

Mix your beans and cheese in a small bowl until they are fully combined, add salt and pepper to taste. Set this aside. In a separate bowl, mix your chopped spinach, cheese, and salt and pepper to taste.

Slightly wet your hands with a water and oil mixture. Grab a golf ball-sized amount of the masa and begin to form it into a ball. Then use your fingers to create a well in the center of the dough. The dough should resemble a small bowl.

Add about 1 tablespoon of the bean and cheese mixture to the well you formed in the pupusa. Pinch the dough together to close it around the mixture. Remove any extra dough.

The pupusa will be in a ball shape. Begin to flatten it out by patting it down, using a clapping motion. Flatten them to be about 1/4 inch thick.

Set them aside and repeat this process to use up the bean and cheese mixture, and continue with the spinach and cheese mixture.

Add about a teaspoon of oil to your griddle or pan. Place the each pupusa on the griddle and let them cook for 3-5 minutes, or until the sides begin to brown. Then flip the pupusas and cook for an additional 3-5 minutes.

Repeat this process until all of the pupusas are done. Serve immediately and enjoy!