Chop the pumpkin into 1/2 cm thick slices and lay flat on a lined baking tray. Drizzle with olive oil and a pinch of salt. Roast for 15 minutes
In a bowl, mix together the passata, basil, garlic and tomatoes.
To assemble, place 2 1/2 lasagne sheets on the base of a deep baking dish. Top with 1/3 of the ricotta, and then place a layer of zucchini slices followed by pumpkin on top. Add 1/3 of the tomato mixture and continue step 4 for the remaining layers.
Sprinkle the cheese on top and cover with aluminium foil. Bake for 30 minutes. Then remove the foil and bake for another 35 minutes.