Courgette
Almost nothing but water and fibre. That is not a criticism: it is exactly why it fills a plate without filling up your day.
How to use it
Grilled, roasted, through a soup, or raw in thin ribbons through a salad. It takes on the taste of whatever you put with it.
The best version
Small and firm, with a glossy skin. A big courgette holds more water, more seed and less taste.
How to prepare it
Leave the skin on, because the skin is where the colour is. If you want it grilled rather than stewed, salt it first and pat the water off.
What it does
Courgette has not been studied in people as a food on its own. It is here for what it does at the table: a large plate with little energy in it, which leaves less room for what you would rather eat less of.
Watch out
Taste a raw piece before you use it. If a courgette is badly bitter, throw it out: that is cucurbitacin, rare in cultivated plants and less rare in ones grown from saved seed.