Preheat oven to 200°C/400°F.

Place the piece of pumpkin in a medium microwave-safe bowl, cover the bowl with plastic wrap. Microwave on HIGH (100%) for 15 minutes or until cooked.

When cool enough to handle; remove the pumpkin from the bowl with tongs and put it on a board. Cut away the skin; scoop out the seeds and throw them away. Cut the pumpkin into slices.

Spray an oven tray with the cooking oil; place the pumpkin slices on the tray, in a single layer. Spray with the cooking oil and season with salt and pepper. Bake for about 20 minutes or until tender when tested with a fork.

Meanwhile, using your hands, remove the chicken meat from the bones; break the chicken meat into large chunks.

Half-fill a large saucepan with water; put a lid on the pan. Heat on the stove over high heat until the water boils. Add the pasta; cook, uncovered, until it is tender (check the instructions on the packet for how long this should take). Place a colander over a large heatproof bowl in the sink. Pour the pasta into the colander; reserve about ¼ cup of the cooking liquid in the bowl and drain the rest down the sink. Return pasta to the pan.

Add the chicken, spinach, cream and the reserved cooking liquid to the pasta in the pan; mix well. Season to taste with salt and pepper.

Spoon the pasta mixture into a 2-litre (8-cup) ovenproof dish. Tuck the pumpkin into the pasta mixture; sprinkle with the cheese and nuts.

Place the dish on an oven tray; place into the oven and bake for about 15 minutes or until the cheese has melted and the top is golden.