The following is simply the empanada dough recipe from the Joy of Cooking with 2 tablespoons of rosemary added to the dry ingredients — and an improvised filling.

I don’t feel the need to roll the dough out systematically. Instead, I pinch off a small ball (approximately 1 1/2 inches in diameter), flatten it on a baking sheet, and fill and bake the hand-pies according to my whim.

Alternatively, you could roll and fill an entire batch, then stick the filled pies in the freezer to bake off in small batches.

Steps

1. Make the dough: Place the flour, rosemary, baking powder, and salt in a large bowl or food processor, and mix with a fork or pulse until combined. Cut the butter and shortening into the flour mixture, using a pastry blender (or old-fashioned cutter, as I did) until the mixture resembles coarse crumbs (about pea-size).
2. If using a food processor, transfer the mixture into a large bowl. Drizzle water over top and mix gently with a fork until the flour mixture is damp enough to form into a ball. Wrap in plastic and refrigerate at least one hour. While the dough is resting, make the filling.
3. Make the filling: Heat the butter in a medium-hot skillet. Add the onion and savory (if using) and cook until the onion is translucent, about 2 or 3 minutes. Add the mushrooms, salt, and pepper, and fry until the mushrooms are soft, about 3 to 5 minutes. Try not to move the mushrooms too much in order to achieve caramelization. Add the potatoes to warm them. (Because the dough is high in fat, I have added few fats to the filling. To enrich the flavor, consider adding cream to the mushroom filling and simmering it until some liquid has evaporated.) Let the filling cool.
4. Make the empanadas: Shape the empanadas by making rounds (the size doesn’t really matter unless you’re unwilling to check inside the oven while the pies are baking; I pinch off a knob about the size of a egg). Place the filling in the center of a round — use a few spoonfuls of filling, not so much that you can’t seal the pastry. The Joy of Cooking calls for an egg-and-milk wash, but I tend to skip this step.
5. Bake at 400 degrees until golden brown (check after 20 minutes).