Place the olive oil into a frying pan and heat over a medium temperature
Add the leeks and cook until they start to soften
Add the herbs and garlic and cook until fragrant
Add the butter and mustard and stir until the butter has melted
Add the flour and stir to mix, and leave to cook for 1 minute
Add the corn and the cream, stir to combine and lower the temperature
As soon as it starts to bubble, turn off the heat and leave it to cool *
Add the chicken and mix to combine, then divide the mixture between 4 cocottes to make individual pies **
Using the lid from your cocotte, cut out 4 circles of pastry
Place the pastry lids over the top of the cocottes and press down using a fork to seal the edges
Trim the edges and make a slit into the top of each pie
Place the cocottes onto a baking tray and place the baking tray into the oven and bake for 30 minutes
Remove the baking tray from the oven, place each cocotte onto a plate, scatter the tops with the thyme and serve
Notes
* The recipe called for stock which I did not add, but if you think the sauce is too thick, add vegetable stock to loosen it. ** Do not overfill the cocottes.