Salvadoran Pupusas con Curtido (Masa Cakes with Cabbage Slaw)

Make the pupusas: Combine the masa harina, salt, and water in a mixing bowl. Knead to form a smooth, moist dough with a playdough-like consistency. If the mixture is too dry, add more water, one teaspoon at a time. If the mixture is too sticky, add more masa harina, one teaspoon at a time. Cover the bowl with a clean towel and let stand for 10 minutes.