Beef and Mushroom Empanadas

For the dough:

all-purpose flour

salt

/2 sticks unsalted butter (cut into cubes and chilled)

egg (room temperature)

water

For the chimichurri sauce:

fresh parsley (finely chopped)

fresh oregano (finely chopped)

spring onion (finely chopped)

garlic clove (finely chopped or grated)

small red chili pepper (seeded and deveined, finely chopped)

red wine vinegar

fresh lemon juice

light olive oil

For the filling:

vegetable oil

portobello mushrooms (finely chopped)

ground beef

small onion (finely chopped)

large carrot (finely chopped)

salt

freshly ground black pepper

garlic cloves (finely chopped or grated)

ground cumin

dried oregano

tomato puree

pitted green olives (finely chopped)