1. Preheat the oven to 180C. 

2. Cook the pumpkin whole on a roasting tray for around 1 hour 30 minutes, then remove from the oven.

3. Meanwhile, peel and roughly chop the onion, put it into a medium pan on a medium-low heat with a lug of oil, the thyme and a pinch of salt and pepper, and cook for 10 minutes, stirring occasionally.

4. Stir in the frozen spinach, cover with a lid and allow to slowly cook for another 15 minutes, or until the liquid has evaporated, then remove from the heat.

5. Cut the squash in half, discard the seeds and skin, then mash up with a fork. Keeping them separate, season both the squash and spinach to perfection with sea salt, black pepper and a grating of nutmeg.

6. Peel and finely slice the garlic, then put it into a shallow 28cm casserole pan on a medium heat with a splash of oil and fry for a couple of minutes, or until lightly golden.

7. Pour in the passata, then add a splash of water to the empty jar, swirl it around and pour it into the pan. Bring to the boil, simmer for just 3 minutes, then season to perfection.

8. On a lean work surface, lay out the pasta sheets facing lengthways away from you.

9. Working quickly so your pasta doesn't dry out, brush them with water, then evenly divide and spread the squash over the sheets. Sprinkle over the cooked spinach and crumble over the feta.

10. Roll up the sheets and cut each one into 4 chunks, then place side by side in the tomato sauce. Finely grate over the parmesan, then pick the sage leaves (if using), toss in a little oil and scatter over the top.

11. Bake for 35 to 40 minutes at the bottom of the oven until golden and crisp. Delicious served with a fresh green salad.

Easy swaps

• If you don't have fresh lasagne sheets, you can use dried. Simply cook them according to the packet instructions, then drain and refresh under cold water, so they're cool when you come to use them.

• Swap out the spinach for whatever greens you've got: think chard, kale, rocket or a mixture.

• If you're out of parmesan, just swap in a bit of cheddar cheese instead.

• Other pumpkin or sweet potato would work really well in place of the butternut pumpkin.

• I've used passata here, but tinned plum or cherry tomatoes would be absolutely fine.

Jamie: Keep Cooking and Carry On, Fridays 7:30pm only on 10.