HEAT oven to 375°F. Spray baking sheet with no-stick spray.
Dough: COMBINE masa flour, wheat flour and salt in medium bowl. Cut in butter using pastry blender until pea-size chunks are formed. Add egg and water, by the tablespoon, to flour mixture, until dough comes together to form a ball. Rest for 10 minutes. Divide dough into 8 equal pieces. Roll each piece into a 6 1/2-inch circle.
COOK ground beef and onions in a large skillet over medium-high heat, breaking up any lumps, until evenly browned and no longer pink. Drain. Add taco seasoning, tomatoes, green chiles, potato, garlic and water. Cook and stir 3 minutes or until most of water is absorbed. Stir in cheese. Season to taste with salt and pepper.
DIVIDE the filling evenly, about 1/3 cup, onto the lower half of dough circles, keeping it about 1/2-inch from edge. Fold dough in half. Crimp edges with fork to seal. Place empanadas on baking sheet. Brush with corn oil. Prick tops with tines of fork to vent. Bake 30 minutes or until golden brown.
Calories from Fat240g
Total Fat 27g
Saturated Fat 14g
Polyunsaturated Fat 0g
Monounsaturated Fat 0g
Total Carbohydrates 31g
Dietary Fiber 3g
Vitamin A 0%
Vitamin C 0%
Vitamin D 0%
*Percent Daily Values are based on a 2,000 calorie diet