If you catch wilted salad leaves before they turn completely, you can use them in soup much as you would spinach or cabbage

There’s a fine line when a bag of salad turns. One minute, it’s perfect, and the next it has turned into compost. To save a wilting salad, chefs are taught to refresh it by picking out and discarding any imperfect leaves and gently plunging the rest into ice-cold water (the addition of a large pinch of salt and acidulating the water with a splash of vinegar or lemon juice will help clean the leaves and remove any unwanted odours). Carefully lift the leaves out of the water rather than drain them, otherwise sand and dirt might cling to them.

If your leaves are no longer fresh and appetising-looking, but still fine to eat, why not cook them? Salad leaves make a great substitute for leafy greens such as spinach, kale or cabbage. Just about all bagged salads, which often contain baby spinach, rocket and beetroot leaves, can be turned into the most delicious soup.