Prepare all the vegetables first: cut the onion and chop the garlic; wash and slice mushrooms, cut the courgette and wash the spinach.
Boil the water in a medium-size saucepan and add spaghetti to it which you cook for around 10 minutes.
While pasta is cooking, prepare the sauce. Heat up the rapeseed oil in a tall frying pan and saute sliced red onion for 2-3 minutes before adding chopped garlic which you leave to cook for a few moments before adding a couple of tablespoons of water to prevent sticking.
Add mushrooms, courgette and 1/2 stock cube and cover the pan to let the vegetables release their own water and cook in the steam. Add basil. Leave it to cook for a few minutes before stirring and covering with the lead again.
Check again in 2-3 minutes to see how much water has evaporated. You want most of the water to evaporate, but not to the extent when it gets sticky. There has to be some liquid left before you add the passata.
Once you add the passata, cook the sauce for a few more minutes or as long as required, until the sauce begins to thicken a bit. This is when you add the washed spinach and cover the pan so that the steam could wilt the spinach.
Finally, you stir the spinach into the sauce and add salt and pepper if required.
Serve with some parmesan cheese on top and side salad.