The great British pasty, I love 'em, and these corned beef, potato and onion pasties are a retro throwback to the sort of ingredients that were prevalent when I was growing up. They taste awesome and are perfect served with baked beans, and they make me feel like a kid again!
Cut the onion in half, peel it and then cut it into 2-3mm (⅛") half-moon shapes.
Heat a 30cm or 12" frying pan over a medium heat, add the butter and then the onions, cook for 10 minutes, stirring occasionally. You want to sweat the onions down without adding colour, so if they start to brown, turn the heat down a little.
Break up the corned beef into a mixing bowl.
Drain the tin of potatoes, then lightly crush them to break them up a little; the bottom of a jar is ideal for this, then add them to the corned beef. You are looking for a mix of sizes, so don't be too particular.
Add the pepper to the mix and have a taste; add salt if required.
When the onions have softened, add them to the corned beef mix and stir to combine.
Cut the pastry in half and roll it out to around 3-4mm (between ⅛" & ¼"), then cut it into a 22cm (9") circle. Repeat with the second piece of pastry.
Add half of the pasty filling to the pastry, brush the edge facing you with a little water, fold over the pastry, and push down to seal the edges. Crimp by pinching between your thumb and forefinger, pull and twist, then move on to the next crimp. There is a visual guide for doing this further up the page.
Beat the egg and then brush this over the pasties, add a sprinkle of coarse sea salt, and bake in the oven at 180°C or 350°F for 35-40 minutes.