Cook at least 2 hours before you want to eat
Preheat oven to 200 degrees C
Sprinkle chicken with salt and pepper and drizzle with olive oil. Place on a baking tray and roast for 8 minutes on each side
Set aside to cool, then shred chicken and place in a large bowl. Reserve pan juices.
Melt butter in a pan and cook mushrooms for 5 minutes
Add leek, garlic and onion. Cook until tender
Add mustard and flour, reduce heat to low and stir constantly for 2 minutes
Whisk in chicken stock, cream and pan juices. Simmer until sauce thickens (about 5 min)
Stir in chicken and season with salt and pepper. Refrigerate until cool.
Line base of 4 pie tins with baking paper.
Cut shortcrust pastry into 4 circles about 2cm diametre wider than the rim of the pie tin. Place pie tin right way up on the centre of the circle of shortcrust pastry. Cut 3 slits from the edge of the pastry to the base of the pie tin.
Cut puff pastry into 4 circles the same size as the rim of the pie tins
Oil paper, then line with shortcrust pastry. Overlap shortcrust at slits to forms solid pie base- bind overlapping pastry together with egg if necessary
Place a piece of baking paper inside pastry and fill with uncooked rice/dried kidney beans/pie weights
Cook at 200 degrees for 10 minutes
Remove rice/beans/weights and inner piece of baking paper
Cook for a further 5 minutes
Spoon pie mix into pastry case.
Drape puff pasty lid over the top and using egg as glue, pinch gently into shortcrust case to seal in the filling. Cut slits in the top of the puff pastry.
Brush the top of the pie with beaten egg and sprinkle over sesame seeds
Bake for 40 minutes or until puff pastry is golden brown.
Can be served with green beans- yum.