Steak and vegetable pasties

Method

1. To make the pastry, place the flour, mustard powder and salt in a large bowl. Add the diced fats and rub into the flour using your fingertips until the mixture resembles fine breadcrumbs.
2. Stir in 45-60ml (3-4tbsp) ice-cold water and mix with a knife until the mixture begins to stick together. Gather the mixture with one hand and knead lightly on a floured surface to form a smooth dough. Wrap in clingfilm and chill in the fridge for 30 mins.
3. Meanwhile make the filling. Heat the oil in a large pan and fry the steak and vegetables over a high heat for 3-4 mins. Cool, then add the thyme leaves and season with salt and freshly ground black pepper.
4. Preheat the oven to 200°C, 400°F, gas 6. Divide the pastry into 6 equal pieces and roll out each to an 18cm (7in) circle.
5. Divide the filling between the 6 pastry circles and brush around the rim of each circle with water. Bring 2 sides of each circle together over the filling and seal the edge firmly by crimping with your finger and thumb along the length of the join.
6. Place the pasties on a large greased baking sheet. Brush with beaten egg and sprinkle with a little sea salt. Bake for 30 mins, then reduce the oven temperature to 180°C, 350°F, Gas 4, and bake for a further 20 mins (cover loosely with foil if the pastry begins to overbrown).