First, make the filling. Roughly chop the streaky bacon and peel and dice the onion, and fry gently in a little olive oil until the onions are nicely soft and translucent. In the meantime, remove the skins from the sausages.
Once the onions have softened, add the sausage meat and break up with a wooden spoon, frying for a few minutes until the meat is no longer pink.
Next, remove the crusts from the bread. Dip each slice into a bowl of cold water to soften it up, and then squeeze the excess moisture out before adding all the bread to the pan and breaking up with the wooden spoon once again.
Add the In A Pickle Christmas Chutney, season with a generous sprinkling of dried thyme, salt and black pepper, and give it all a really good stir. Then transfer the mixture to a bowl and set aside to cool.
Preheat the oven to 190?C (170?C fan). On a floured surface, roll out the puff pastry to the thickness of a pound coin. Grease an ovenproof dish well with butter, then line with the pastry. Trim it round the edges, but leave a margin of a couple of centimetres all the way round.
Squash the trimmings into a ball and roll out again. Pop your prepared filling into the pastry-lined dish, spreading it out well and pressing it down a little. Then top with the remaining pastry and crimp the edges over tightly.
Break the egg into a small bowl and whisk with a fork, then use a pastry brush to coat the top of the pie with egg, to give it a nice shiny brown crust. Finally, make a small hole (about the size of a 5p) in the middle of the top, to allow the steam to escape.
Pop the pie in the oven and bake for 40 minutes. Allow the pie to cool for a few minutes in the dish before loosening all the way round with a knife and turning out onto a plate to serve.