Step 1

Cook the pasta in a large saucepan of salted boiling water until al dente. Drain. Transfer to a large bowl.

Step 2

Heat the oil in a large saucepan over medium heat. Cook the leek, garlic and thyme, stirring, for 3-4 minutes or until soft. Increase heat to high. Add the mushroom, broccoli and pumpkin. cook, stirring, for 5 minutes or until the vegetables are soft. Stir in the spinach. Remove from heat.

Step 3

To make the cheese sauce, place 500ml (2 cups) of milk in a saucepan over medium heat and bring almost to the boil. Combine the cornflour and remaining milk in a jug. Stir into the hot milk. cook, stirring, for 5 minutes or until the mixture boils and thickens. Stir in the ricotta and 80g (1 cup) of cheese until combined. Season with salt and pepper.

Step 4

Stir the pumpkin mixture and sauce into the pasta. Transfer to a 3L (12-cup) capacity baking dish. Sprinkle with the remaining cheese. Set aside to cool slightly.

Step 5

Preheat oven to 200°C. Cover with foil. Bake for 40 minutes. Remove foil and bake for a further 15 minutes or until golden.