Heat the oil in a large saucepan; add the onions, garlic, carrots and zucchini. Fry until vegetables are soft and fragrant (about 3 minutes). Add the beef and fry until browned. Add the tomato paste; pour in the wine and boil until it has reduced and thickened. Reduce heat and stir in the Passata, vegetable stock powder (or salt), and oregano.

Cover pan with a lid and simmer until the sauce has thickened, stirring occasionally (about 20-30 minutes). Turn off heat; add the cooking cream (or milk) and stir until combined.

Cook the spaghetti in a pot of boiling salted water. Drain; add 2 ladlefuls of the sauce and mix until pasta is covered. Divide between 6 serving dishes; top with extra sauce and sprinkle with Parmesan cheese and parsley.