Heat the oil in a large pan. Add the onion, carrots, butternut squash, leek, courgette and mushrooms and cook over a high heat for 5 minutes to soften.
Add the passata and stock, bring to the boil, then reduce the heat, cover and simmer for 10 minutes. Meanwhile, cook the linguine or tagliatelle in a large saucepan of lightly salted boiling water for 8–10 minutes until tender, then drain and return to the pan.
Using a hand-held blender or food processor, blend the sauce until smooth, adding a little water if necessary. Season with salt and pepper, then toss with the linguine or tagliatelle. Serve with plenty of grated cheese.