Melt 2 tablespoons of the butter in a medium skillet over medium heat. Saute the onions until they just begin to brown. Then stir in the garlic and cook until the aroma is released, about 1 minute longer. Add the mushrooms, salt, pepper and arbol chiles. Continue cooking until the mushrooms soften, 5 minutes. Stir in the epazote or parsley and briefly cook just to release its flavor, about a minute. Set aside to cool.
Divide the corn tortilla dough into 16 equal balls and flatten to 1/4-inch thick, 3-inch circles Divide the cooled mushroom mixture into 16 portions.
Lightly coat one side of each tortilla with the remaining softened butter. Place the mushroom mixture in the center and top with 1 tablespoon of the grated cheese mixture. Fold over to enclose and pinch the edges together tightly to seal. Refrigerate, covered with plastic wrap, a minimum of 30 minutes or up to 2 days.
Pour the oil into a medium saucepan and place over medium high heat. When the oil is hot, fry the empanadas, a few at a time, until they color slightly and rise to the surface, about 7 minutes. Transfer to paper towels to drain.
To serve, split each empanada open along the seam and garnish with 1 tablespoon each salsa, cabbage, crema, creme fraiche or sour cream. Serve hot.
Note: Use a mixture of equal parts of the following cheeses: Mexican Manchego (substitute Monterey Jack or Muenster if unavailable), Anejo (substitute Romano or dried feta), and Panela (substitute ricotta or dry cottage cheese).
Combine the masa harina, water and salt in a large mixing bowl, and stir until smooth. The dough should be slightly sticky and form a ball when pressed together. To test, flatten a small ball of dough between your palms. If the edges crack, add water to the dough, a tablespoon at a time, until a test piece does not crack.
c.1997, M.S. Milliken & S. Feniger, all rights reserved