Fry the diced onion and chopped thyme in a large saucepan for about ten minutes until the onions have softened.

Add the garlic and cook for a further minute.

Drop in the butter, once it is melted add the plain flour and stir well. Cook for one minute.

Add the beef stock, stir well and then add the Guinness.

In a large frying pan, sear the seasoned beef until it is browned all over. You may need to do this in batches. Once it is a deep brown all over, add the beef to the saucepan. Bring it to the boil, then turn it down to a simmer and cook for about 3 hours, stirring occasionally to make sure it doesn't stick to the bottom.

After 3 hours, add the dijon mustard, parsley, salt and pepper.

Spoon it into a 24 cm pie dish and set aside to cool slightly.

Preheat the oven to 200℃

Brush the edges of the pie dish with a little water, then place a few strips of pastry around the lip of the dish.

Lay the remaining pastry across the top of the pie, pressing down around the edges to seal. use a sharp knife to cut away any excess pastry.

Crimp the edges using your thumb and forefinger of one hand, and the forefinger of the other.

Cut two slits in the top so that steam can escape, then poke two sprigs of rosemary in.

Brush the pastry with the beaten egg.

Place the pie into the oven for 25-30 minutes, until it is puffed up and golden. When it looks done, it is done.