Potato, Pepper, and Chorizo Empanadas

Empanada Dough

2 1/4 C flour, AP
1 1/2 t salt
4 oz butter, unsalted, cold and cut in 1/2-inch cubes
1 large egg
1/3 C ice water
1 T distilled white vinegar

Filling

3/4 C Spanish chorizo, finely chopped (3 oz)
2 T olive oil
2 onions, finely chopped
1 medium red bell pepper, finely chopped
1/2 medium green bell pepper, finely chopped
1 bay leaf
1/2 t salt
1/4 t dried oregano, crumbled
1/2 lb Yukon gold potato (about 1 large)

1 egg, lightly beaten with 1 T water

Make the dough:
Sift flour with salt into a large bowl and blend in butter with your fingertips or a pastry blender until mixture resembles coarse meal with some (roughly pea-sized) butter lumps.

Beat together egg, water, and vinegar in a small bowl with a fork.  Add to flour mixture, stirring with fork until just incorporated. Mixture is meant to look a little shaggy

Turn out mixture onto lightly floured surface and gather together, then knead gently with heel of hand once or twice, just enough to bring dough together.

Form dough into a flat rectangle and chill, wrapped in plastic wrap, at least one hour. In the meantime...

Make the filling:
Cook chorizo in oil in a 2 1/2-3 quart heavy saucepan over moderate heat, stirring, 2 minutes, then transfer to a medium bowl with a slotted spoon.

Add onions to saucepan and cook, stirring frequently, until golden and very soft, about 15 minutes.

Add garlic, bell peppers, bay leaf, salt, and oregano and cook, stirring frequently until peppers are very soft, about 15 minutes.

Peel potato and cut into 1/2-inch pieces, then stir into onion mixture and cook over moderately low heat, covered, stirring frequently, until potatoes are just barely tender, 10-12 minutes.

Add potato mixture to chorizo and stir to combine.

Cool filling to room temperature and discard bay leaf.

Form and Bake empanadas:
Put oven racks in upper and lower thirds of oven and preheat to 400.

Divide dough into 12 equal pieces and form each into a disk.  Keeping remaining pieces covered, roll out 1 piece on a lightly floured surface with a lightly floured rolling pin into a 5-inch round (about 1/8-inch thick)

Spoon about 2 T filling onto center and fold dough in half, enclosing filling. Press edges together to seal, then crimp decoratively with your fingers.

Transfer empanada to baking sheet.  Make 11 more, arranging on 2 baking sheets.

Lightly brush empanadas with some of the egg wash and bake in upper and lower thirds of the oven, switching halfway through baking, until golden, about 25 minutes

Transfer empanadas to a rack to cool at least 5 minutes.  Serve warm or at room temperature.