Heat your oven to 180°C/356°F. Wrap your bulbs of garlic in baking parchment, then place on a baking tray and roast for 45 mins. Set aside until cool enough to handle. Squeeze your garlic out of it’s skin by pressing a knife down on it. Discard the skins, saving the caramelised flesh until later.

Take two thirds of your pastry and roll it out to 2mm thickness. Line your pie dish with your pastry, folding it into the edges on the base and pressing into the sides so that it sits snug against the sides of the dish. Line with a square of parchment and fill with baking beans, uncooked rice or uncooked pulses.

Pop your pie dish in the oven for 10 mins until your sides have puffed up and crisped slightly. Carefully remove your baking beans and parchment, then whack in the oven for 5 minutes longer until you have a crisp base. Turn up the oven to 190°C/374°F.

Chop your chicken into 2 inch pieces. Slice your onion.

Heat a large saute pan over a medium heat. Add a little olive oil, then tip in half of your chicken thigh chunks. Season with salt and pepper and fry over a high heat for 5 mins until it has gone nice and golden. Remove from the pan, then repeat with your remaining chicken.

In your empty pan, add your butter and let it melt. Tip your onions into the same pan along with your rosemary and thyme sprigs. Cook over a medium heat for about 6 mins until totally soft. Add your pancetta and turn up the heat, frying until your pancetta is crispy and the onions are caramelised.

Add your flour and cook out for 2 mins until it starts to smell biscuity, then gradually pour in your stock in small increments, whisking all the while to ensure you have a smooth sauce. Once your stock has finished, do the same with your milk. Bring to a boil, then simmer for 2 mins until your sauce has thickened.

Add your chicken and roasted garlic to the pan along with some salt and pepper, and stir to combine. Simmer for 2 mins.

Pour your filling into a pie dish and top with your pastry. Beat your egg and brush this over the top of your pastry. Place on a baking sheet in the oven and bake for 25-30 mins. Serve up by itself, or alongside some mash and greens.