This is a good old fashion pasty that brings back fond memories of family holidays spent in Cornwall when I was growing up. In the 18th century it was a staple diet for working men, like Miners & Farm Workers, across Cornwall because of its size & shape, which was easy to carry around, the pasty protecting the the wholesome food inside. The ultimate 'packed lunch' where everything is edible.
Although the recipe is many years old, first known reference is as far back as the 13th century, it's still a popular dish which is made & sold all over the U.K.
Pre-heat the oven to fairly warm - Gas Mark 6 : 400F/204C. Have ready a baking sheet & a plate or saucepan lid about 6 inches in diameter.
Wipe the chuck. Steak with a clean, damp cloth, preferably muslin & cut into small pieces. Peel the potatoes & cut into small, diced pieces. Mix the chuck steak, potatoes, onion & carrot together in a mixing bowl with the water or stock & season well. Put to one side.
Make the Short Pastry: Sieve the flour & salt into a mixing bowl. Rub in the margarine until it looks like fine bread crumbs. Mix in the water to form a firm dough.
Roll out thinly & cut into round by placing the plate or saucepan lid on top the pastry & cut round with a pointed knife. Form the scraps into a ball & repeat. Place the filling in the centre of each round.
Brush the pastry edges with water. Bring the edges up & over the filling & press gently together all round to seal. Flute the edges or fold & twist neatly with the finger tips.
Place on the baking sheet & brush with beaten egg or milk. Bake in the pre-heated oven for 30 minutes; then turn the oven down to Gas Mark 3: 335F/168C & bake for a further 40-45 minutes.