Cut the squash into small cubes. Melt the butter in a pan, add the olive oil. Add the squash and onion stir through the butter and oil, cook over a medium heat with a lid on, turn the squash and onion now and then and cook until soft and lightly golden on the outside. Add the chopped sage and cook for 2 minutes. Remove from the heat and spoon into a large mixing bowl to cool down.
Drain the ricotta on kitchen paper for 5 minutes and trim the rind away from the taleggio and chop into small pieces.
Once the squash and onion are cooled, add the ricotta and taleggio followed by the parmesan, lemons zest and juice, nutmeg, sea salt, black pepper, pine nuts and then crumble in the amaretti biscuits. Mix everything together, mashing the squash slightly. Taste the mixture and adjust the seasoning to please your palette.
Next, you will need a deep gratin, roasting or pie dish. Start the layering with some of the béchamel (keep plenty for the top, so use about 4 tablespoons) then 2 lasagne sheets, 1/3 of the butternut, 1/3 of the spinach, a little béchamel then 2 more lasagne sheets and so on. Finish with lasagne sheets and plenty of béchamel. Top with a good even sprinkle of Parmesan and pine nuts.
Bake at 190cc/180cfan/gas5 for 30-40 minutes until bubbling and golden.
Butternut filling
The rest