Add potatoes to water and boil with a pinch of salt for 20/30 mins till soft
Then drain allow to cool a little

In the meantime while the potatoes are boiling chop a small Onion and in a pan add a large knob of butter and once melted add the onions and sauté

Mash the potatoes and add to the onions

Now add the mash top with remaining cheese then cover with the other half of the pastry prick again with the fork and then egg wash it

Put oven on for around 40 mins till the top is golden and cooked
I served with beans coleslaw and salad