Heat oil in a large skillet. Add the chicken and cook for about 5 minutes, until the chicken is browned all over. Using a slotted spoon remove the chicken and keep to one side.
Throw the bacon in the pan and cook for a bit before adding the leek and the mushrooms. Carry on cooking for about 3 minutes stirring occasionally until the leeks are kinda soft. Remove all of this and stick it to the side with the chicken.
Add the butter to the pan and melt over a medium heat, add the almond flour and stir well to incorporate all the flour into the butter - kinda paste like. Then slowly add the hot chicken stock, stirring all the time until a smooth gravy is created, cook and stir for about 3 minutes. At this point, you might want to transfer it to a bigger pot (like a dutch oven thingie) unless you have a really big skillet. Add the chicken, leeks, bacon and mushrooms into the gravy, add the parsley and thyme and season generously with sea salt and black pepper.
Let this simmer on a low heat for about 10 or 15 minutes - it'll sorta thicken up. While it's doing that, make the 'crust'.
Whizz the parmesan and almond flour together in a food processor.
Sprinkle a tablespoon or more into a non-stick frying pan in a pancake sorta shape - not too big - and cook until melted/crispy. Then flip.
I made about 4 lids. Do them individually, then leave to cool off on a plate. Dish out the pie filling and top with a cheese lid.
I served this with celeriac.