Preheat the oven to 200°C.
Toss the pumpkin with olive oil, salt and pepper and roast for 25–30 minutes until tender and lightly caramelised. Set aside.
Meanwhile, heat a splash of olive oil in a large pan and cook the garlic for one minute. Add the passata, oregano and basil and simmer gently for 10 minutes.
Wilt the spinach in a separate pan, then allow it to cool slightly before squeezing out any excess moisture. Mix with the ricotta and season well.
To make the cheese sauce, melt the butter in a saucepan, stir in the flour and cook for one minute. Gradually whisk in the milk until smooth. Simmer until thickened before stirring through the grated cheese and nutmeg. Season to taste.
Lightly grease a large baking dish.
Spread a little tomato sauce over the base, then layer with lasagne sheets, pumpkin, spinach and ricotta mixture, mozzarella, cheese sauce and more tomato sauce.
Repeat the layers until all ingredients are used, finishing with cheese sauce, mozzarella and parmesan on top.
Bake for 35–40 minutes until golden and bubbling.
Allow to rest for 10 minutes before serving.
Serve with a crisp green salad and warm crusty sourdough or garlic bread.
A sprinkle of fresh basil and a little extra parmesan just before serving finishes it perfectly.