I got this from an Ortega cookbook. These may be filled one day ahead and chilled in one layer on a lightly floured plate, covered. Reseal edges if necessary.
Heat 2 teaspoons oil in a 12 inch nonstick skillet over moderately high heat until hot but not smoking; cook chorizo and onion, stirring until onion is softened.
Add potatoes and salt and pepper.
Cook, covered, stirring occasionally until potatoes begin to turn golden brown, about 6 minutes.
Stir in jalapenos, tomatoes and cumin.
Transfer to a bowl and cool completely.
Stir in cilantro, cheese and additional salt and pepper to taste.
Roll out each empanada wrapper into a 6 inch round on a floured surface.
Put about 1/3 cup filling in center of each wrapper and form filling into a log.
Moisten wrapper edges with a finger dipped in water.
Fold each wrapper over filling to form a half moon.
Press down around filling to force out air.
Seal by pressing edges together firmly with a fork.
Heat remaining 3 cups oil in a deep 12 inch skillet over moderate heat until hot but not smoking.
Fry empanadas in 3 batches, gently turning,until golden brown, about 3 minutes.