Start by gently frying the sliced leeks in a large non-stick pan with the rapeseed oil on a low heat. Season with a generous pinch of salt and continue to sweat the leeks for around 8 minutes until softened.
Once the leeks have softened, add the fresh thyme, chopped swede and carrot and sliced chicken breast into the pan. Season with black pepper and fry the ingredients in the pan, increasing the heat to medium and continuously stirring for around 8 minutes. We’re not aiming to fully cook the chicken, swede and carrots at this stage, as they will continue to cook in the oven.
Now add the garlic into the pan to fry for a couple of minutes, before slowly adding the stock and reducing the heat to low to simmer for 15 minutes. Then, slowly pour the cream into the mix. Add the frozen peas and ham at this stage and the white wine vinegar. Stir in the cornflour (mixed with a little water).
Once the sauce has thickened, the creamy pie filling should be ready.
Divide the creamy pie filling into 5 ovenproof dishes/ramekins. Store in the fridge for up to 5 days or alternatively freeze half of the batch to consume at a later date.
When it’s time to eat, add the puff pastry onto your ramekins with a couple of cm excess pastry for crimping. Use either an egg wash or a milk wash over the crust for a beautiful golden hue. Pierce a hole in the pastry.
Pop in the oven for 25 minutes and remove to serve when the pastry is golden brown.