Method

1. Heat the oven to 220C/200C fan/gas 8. Put the pancetta and onions in a large casserole dish (ours was 30cm) and drizzle over 1 tbsp of the olive oil. Season and roast for 20 mins until the pancetta is sizzling and caramelised at the edges. Scoop into a small bowl.

2. Meanwhile, prepare the squash. Thinly slice the long neck into roughly 3-5mm thick rounds, then put in a large bowl (noneed to peel). Stir in the garlic, 2 tbsp of the oil and the chopped sage to combine.

3. Combine the lemon zest and mascarpone with some seasoning, beating well to loosen. Put the spinach in a colander in the sink and pour over boiling water from the kettle so it wilts. Leave until cool enough to handle, then put in a tea towel and squeeze out any excess water.

4. Spread some of the lemony mascarpone over 3 of the lasagne sheets, then arrange them in the base of the casserole dish you used for the pancetta. (The base won’t be covered evenly with lasagne sheets, but don’t worry – it will all come together.) Sprinkle over some of the pancetta, onion and spinach, then top with a layer of squash slices, covering any gaps left between the lasagne sheets. Top with more lasagne sheets covered in mascarpone, then repeat with the rest of the pancetta, onion and spinach, finishing with a layer of squash.

5. Carefully pour over the stock, then sprinkle over the parmesan. Bake for 35 mins, or until golden and bubbling, and a small knife passes through the lasagne with ease. Leave to cool for 10 mins before serving.