Using a food processor

Put the flour and salt into the machine and briefly process to combine.

Dice the butter (plus lard if using), add to the machine and process until the mixture looks like very fine breadcrumbs.

With the motor running add iced water, 1 tbsp at a time, until the mixture comes together into a smooth ball.

Making by hand

In a medium sized bowl, stir together the flour and salt.

Coarsely grate in the butter (plus lard if using): dip into the flour now and then to prevent sticking. Using your fingertips, rub the fat into the flour until the mixture resembles fine breadcrumbs.

Add 2 tbsp of cold water and stir in with a round bladed knife. Continue adding tablespoons of water and stirring until the mixture starts coming together.

Use your hands to bring together into a smooth ball.

Using digital scales, divide the pastry into 6 pieces.

Flatten each piece into a disc then wrap in foil or place in a reusable polythene bag and chill in the fridge for at least 30 minutes.

Make the filling while the pastry is chilling.

Tip: pastry can be chilled for longer if more convenient or frozen.

Put the prepared potatoes and onions in a saucepan, more than cover with cold water and season to taste with salt.

Bring to a boil and rapidly simmer until just tender (don't let them get too soft).

Drain and set aside to dry and cool.

Put the cooked potatoes, onions, and grated cheese into a bowl along with the black pepper plus dried thyme or other seasoning.

Stir until combined, taste and add more seasoning, including salt, if you think it needs it.

On a lightly floured surface, ideally covered with a silicone mat, roll out the first piece of pastry dough into a circle approximately 19 cm in diameter (about the size of a side/tea plate.

Put ⅙ of the filling on one half of the circle, leaving a 1 cm bare edge. Lightly press the filling down to prevent air gaps. Brush the edge with some of the beaten egg (or milk) then bring the dough over to cover the filling and create a semi-circular pasty.

Press the edge down well to seal. To create a pattern either go around again pinching with your fingers to create a wavy edge or press down with the tines of a fork.

Repeat the process with the remaining pastry dough and filling.

Tip: pasties can be stored in the fridge and cooked later, or frozen at this stage.

Preheat the oven to 200°C / 180° Fan / Gas 6 / 400° F.

Line one large or two regular baking trays with baking paper and transfer the pasties onto them.

Brush a layer of beaten egg over the top of the pasties and sprinkle over the seeds if using.

Make 2 cuts with scissors or a knife in the top of each one to allow steam to escape.

Put the tray(s) in the oven and bake for 25 minutes or until the pastry is crisp, golden, the filling hot and starting to bubble a little through the steam vents.

Tip 1. If your oven cooks unevenly, turn the pie around after the first 15 minutes.

Tip 2. After 15 minutes add another layer of beaten egg for a deeper glaze.

Tip 3. If the steam vents start to close, gently reopen with a knife.

Transfer the pasties to a wire rack and rest for 5 minutes before serving. Can also be eaten cold.

Pasties will keep for 3 days in the fridge or can be frozen.

Reheat at 180°C / 160° Fan / Gas 4 / 350° F until hot (approx. 20-25 min) or heat in a microwave for 1 - 2 minutes until the filling is hot then put in the oven at the temperature above (or air fryer) for 4 - 8 minutes to re-crisp the pastry.