Cut the squash in half lengthways and scoop out the seeds with a spoon. Place, skin-side down in a large baking tray and drizzle with the olive oil. Bake for 50 mins - 1 hour or until the butternut squash flesh is tender. Leave to cool
Reduce the oven temperature to 190c/170 Fan/Gas Mark 5
When the squash has cooled enough to handle, scoop the flesh out into a bowl. Use a potato masher to mash until smooth. Stir in the sage and nutmeg. Season well with salt and freshly ground black pepper.
In a large, ovenproof dish, layer the butternut squash mash with the crushed Amaretti biscuits, parmesan and lasagne sheets. Finish with a layer of lasagne sheets topped with white sauce and Parmesan. Season with freshly ground black pepper
Cover with aa piece of foil that has been lightly oiled, or parchment lined foil and bake for 30 minutes. Uncover and bake for a further 10-15 minutes until golden. Serve scattered with sage leaves
TIP: You can buy good quality fresh white sauce or jars of white sauce from most large supermarkets. Alternatively, to make your own: Melt 50g butter in a large saucepan. Add 50g plain flour and whisk for 1 minute. Remove from the heat and gradually whisk in 750ml milk until smooth. Return to the heat and bring to the boil, whisking until thickened
