Needless to say, I like my Cornish pasties proper and traditional, no mucking about, no cheese, no mackerel and beetroot (yes, really, saw this on a pasty company's site along with a 'breakfast pasty' with sausage and scrambled egg in it), just meat and vegetables and good pastry.
This is how I make mine. No specific quantities, depends how many you're feeding. I use roughly 2oz of pastry per pasty, and make up the filling by eye.
Dice some turnip (swede in England) and potato quite small, and dice beef to the same size, so all cooks in the same time. Tonight I used a piece of leftover cooked beef, which was quite rare, as in cooked, not unusual lol. Most cuts of beef can be used, never minced though.
Mix the meat and vegetables in a bowl with salt to taste and a decent whack of black pepper. Set aside.
Make your pastry. I use 3/4 butter to flour for a decent, rich, buttery, crisp pastry, so had 8oz flour and 6 oz butter, rubbed in, brought together with cold water.
Divide pastry, roll out into as round a shape as possible, ad cut around a small dinner plate/large tea plate. Pile the mixture in the middle, wash around the edge with cold water, then fold up and crimp. Place carefully on a hot baking tray, prick with a fork and cook in a hot oven for 15 - 20 minutes. I tend not to use eggwash on mine.