1 tbsp chopped flatleaf parsley
200g/7oz leftover cooked vegetables, roughly chopped
50ml/2fl oz leftover beef gravy, plus extra to serve
plain flour, for dusting
2 tsp wholegrain mustard
sea salt and freshly ground black pepper
2 free-range egg yolks, beaten
2 x 375g/13oz ready-made all-butter puff pastry
300g/10陆oz leftover cooked beef, cut into thin slices