Blend flour, butter cubes, and salt in a food processor until the mixture resembles breadcrumbs.
Add cheese, water, and egg yolk then blend until the mixture forms a dough.
Knead the dough on a floured surface for 3-4 minutes until smooth, wrap in cling film, and chill for one hour.
Heat oil in a pan and fry beef mince for 6-8 minutes until browned, then set aside.
Fry onion, carrot, and celery in the same pan for 3-4 minutes until softened.
Return beef to the pan and stir in tomato purée, Worcestershire sauce, and ale.
Simmer for 8-10 minutes until most liquid evaporates.
Preheat oven to 200°C and grease a 20-25cm pie plate with butter.
Divide dough in half, roll out one portion, and line the pie plate.
Spoon the beef filling into the pastry case.
Roll out the second half of pastry, brush edges with egg wash, place on top, and seal.
Brush the lid with egg, prick with a fork, and bake for 35-40 minutes until golden brown.