Prepare pasta as per package instructions.
Meanwhile,heat oil in a large saucepan over a medium-high heat. Add pumpkin, onion, capsicum, mushroom, and garlic; sauté 5 minutes vegetables will begin to soften. Add basil and oregano; saute further 1 minute.
Add tinned tomatoes, vegetable stock and tomato paste to vegetables; stir to combine. Simmer, without bringing mixture to the boil, for 10 minutes. Sauce will reduce and vegetables will become tender.
Drain pasta and serve with half of the sauce. Remaining sauce stays fresh for 24 hours in the refrigerator.
Serve half of the sauce over warm pasta.