Vegetarian empanada recipe

This vegetarian version of the empanada contains a rich spinach and cheese mixture that goes ever so well with pastry. It's like toast and spinach dip rolled into one.
For the pastry:
At most Latin food stores you can find frozen empanada dough discs, which are more expensive but also more convenient. Making dough from scratch doesn't taste much different but is obviously more labor-intensive. You can also customize the ingredients by adding spices and herbs to compliment or contrast with the flavors of the filling.

For around twenty medium empanadas you'll need:

•     3 cups of all purpose flour
•     ¼ teaspoon of salt
•     6 oz of unsalted butter cut into 12 pieces, fresh out of the fridge
•     1 egg
•     4-5 tablespoons of water
•     1 egg, beaten with a little milk

Method:
1.    Combine the flour and salt in a bowl or food processor.
2.    Add the butter, egg and water and mix until it forms into a single lump of dough. No especially vigorous kneading is required. 
3.    Roll into a ball and place in the fridge for about half-an-hour.
4.    Roll out the dough on a cutting board and cut out discs around a small plate or with an appropriately-sized cutter.
5.    They can be used immediately or refrigerated/frozen for later.

For the filling:
You'll need:

•     1/4 cup chopped onion
•     6 ounces baby spinach
•     1/2 cup flour
•     1 cup milk
•     1 clove garlic, minced
•     3 tablespoons butter
•     2 eggs
•     1 cup grated cheese (cheddar, mozzarella, Monterrey jack)
•     2 tablespoons grated parmesan
•     3 tablespoons olive oil
•     Salt and pepper to taste

Method:
1.    Sauté the onion in the olive oil on low-medium heat for a couple of minutes, then add the garlic. Continue to sauté until the onion is soft and golden.
2.    Turn the heat up to medium and stir in the spinach. Cook until spinach wilts, about two-three minutes. Remove from heat and let cool.
3.    Add the flour to a saucepan. Whisk in the milk gradually until smooth, then add the butter and place over a low-medium heat. Cook, stirring constantly, until mixture starts to boil and thicken.
4.    Remove from heat and whisk in the eggs.
5.    Return to heat and cook, stirring, until mixture again boils and thickens to almost a past-like consistency.
6.    Remove from heat and add all the cheeses. Season to taste.
7.    Chop up the cooled spinach and onion mixture. Stir this mixture into the cheese sauce.
8.    Let the mixture cool, as hot filling will loosen up the pastry and make it harder to work.

To make the empanadas:
1.    Pre-heat oven to 400 degrees Fahrenheit.
2.    Spoon some filling into the middle of each pastry disc.
3.    Fold the dough in half over the top of the filling, forming a pocket. Squeeze as much air out as possible and glue the seal with the egg wash. Crimp the edges with a fork or your fingers for a traditional look.
4.    Glaze the crust with egg wash.
5.    Grease or line a baking tray with wax paper and arrange the sealed empanadas.
6.    Bake for twenty to twenty-five minutes or until golden brown.
7.    Serve hot.