In a medium, high-sided skillet, heat olive oil over medium heat for 2 minutes.
Add chopped onion and garlic; gently sauté until soft, fragrant, and translucent.
Stir in chopped tomatoes and cook until they start to caramelise slightly.
Pour in the stock and add the spaghetti, ensuring it’s fully submerged.
Let it cook for about 15 minutes or until the pasta is al dente. If adding sweetcorn, include it at the 8-minute mark.
Gently stir in the double cream, fresh basil, and spinach (if using). Let it sit for a couple of minutes to allow the spinach to wilt.
Serve hot, garnished with additional basil if desired.