A courgette is over 90 percent water. That is the number the whole story starts from and the number that makes the idea work or collapse - depending on what you do with it over the next five minutes.

The idea is simple: courgette instead of pasta. With a spiraliser, a mandoline or an ordinary peeler, you get thin ribbons that look like spaghetti, or wide sheets that replace lasagne and cannelloni pasta. The same courgette also makes ravioli, and even a pizza base.

The difference in nutritional value is real, but it is not what most people think. Courgette gives you very few calories and fills you up early, plus fibre, vitamin C, folates, potassium and antioxidants. Pasta gives you complex carbohydrates - which means energy. Those are not the same thing and they do not substitute for each other. This is a variation, not an upgrade.

The key is in one step people skip. The mild taste of courgette means it absorbs sauces well - but only if the texture has stayed firm. Overcooked courgette is not spaghetti, it is water on a plate. Which is why the cooking time is everything: a brief touch of the hot pan and straight out again.

A few of the suggestions are worth singling out. Fake cannelloni with tomato sauce, fifty minutes, for four. Ravioli with feta, spinach, tomato and peppers, forty-five minutes. Fake lasagne with courgette and tomato, twenty minutes - the fastest of them all. Courgette spaghetti with prawns and cherry tomatoes, thirty-five minutes.

The shortest version is for one person: courgette spaghetti, twenty minutes, done. That is a portion that makes sense when you are home alone and do not fancy putting a pot of water on the hob in August.

Courgettes are in every market right now and among the cheaper things you can buy. That does not mean this recipe should replace every plate of pasta - it means that when you have three courgettes left in the fridge, you know what to do with them besides frying them.