In a food processor, mix together salt and flour.

Add in cubes of butter and pulse a few times until combined.

Continue to pulse as you add in egg and slowly pour in water, only using as much is needed for dough to come together in clumps.

Take dough out of food processor and divide into two balls. Flatten each ball into a disc shape.

Dough is ready to use immediately (or can be refrigerated for later use).

Heat oil in large frying pan on medium heat. Add in sliced onions and sauté for a few minutes.

Add in mushrooms and continue to cook for10 minutes, until tender.

Add in balsamic vinegar, brown sugar and raisins if using. Cook for a further 5 minutes then remove from heat and chill in the fridge.

Pre-heat oven to 190˚C (375˚F) and line two baking trays.

Roll each ball of dough out till it is about half a centimetre (1/4 inch) thick.

Using a circle-shaped cutter, cut out circles from dough (we used a small bowl with a 12cm diameter to yield 20 empanadas).

To assemble, put a spoonful of filling in the middle of each empanada circle.

To seal, fold the circle in half and press the edges with your fingers. For a basic seal, use a fork to press along the edges.

If you want to attempt a repulge, gently use your fingers to curl the edges into themselves.

Using a pastry brush, coat empanadas with egg wash.

Put complete empanadas on lined baking tray and refrigerate empanadas for 30 minutes (this helps seal in the fillings before baking).

Once refrigerated, stick baking trays in oven and bake empanadas for 18-23 minutes or until golden.