In a mixing bowl, weigh out the flour, salt, butter and Lard.

Rub the fats into the flour before adding the water to make a dough.

Wrap in cling film and place in the fridge to rest for about 30 minutes.

Whilst the pastry rests make the filling.

Wash the potatoes peel and, cut into chunks about 1 -2 cm and place in a pan of cold water. Add the onion to the potatoes and bring to the boil, then simmer till cooked but not mushy.

Drain the potatoes and onion and return to the pan. Now add the corned beef, ketchup, chopped tomatoes and the dissolved beef stock cube.

Mash the ingredients together but make sure you leave some lumps of potato for texture.

Cover the filling and set aside to cool whilst you roll out the pastry.

Preheat your oven to 200ºC/Gas 6 and Lightly oil a rectangular baking tray, (with a small lip round the edge..

Take half of the pastry and roll it out to fit the tray, trim off any excess.

Brush the pastry base with egg wash and prick all over with a fork and bake for 15 minutes to seal the base before you add the filling.

Whilst the base is baking you can roll out the rest of the pastry for the top.

Now you can add the filling and cover with the pastry lid. Crimp the edges with your fingers or a fork and prick the top several time with the fork, this will allow steam to escape and ensure a nice crispy top.

Egg wash the top and bake for a further 30 minutes or until the top is a nice golden brown.