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.

Salad bag soup

Wilted salad leaves aren’t especially appealing, but if you catch them before they turn completely, use them up in this wonderfully simple, super-quick, protein-rich and vibrant green dish. Remove and discard any bruised leaves, wash in cold water, then fold into the soup base and blend.

I often use cooked white beans to thicken my soups as a nutritious alternative to potatoes, and because I like their subtle flavour, but on this occasion I had run out, so used chickpeas instead. To make that familiar chickpea flavour make more sense, I also added some toasted cumin and a squeeze of lemon juice, and they worked a treat.

This dish is similar to watercress soup, so I’d serve it with a drizzle of double cream on top, along with a swirl of extra-virgin olive oil and lots of freshly ground black pepper.

Serves 2

2 tbsp olive oil
1 onion, peeled and finely chopped (about 100g)
1 large garlic clove, peeled and roughly chopped
400 tin white beans, or chickpeas, including the liquid
50-100g prepared salad leaves

Optional toppings
A squeeze of lemon
Extra-virgin olive oil
Cream
Soft goat’s cheese, crumbled
Toasted spices, such as cumin, coriander and/or nigella seeds

Put a good glug of oil in a saucepan on a medium-high heat. Before the oil gets too hot, add the onion and garlic, and cook, stirring occasionally, for two to three minutes, keeping an eye on the heat to prevent any browning.

Add the white beans and the aquafaba from the tin, then pour in enough boiling water to cover everything by about a centimetre. Bring to a boil, then turn down to a simmer and cook for three minutes. Off the heat, fold in the salad leaves, then blend smooth and season to taste. Top with extra-virgin olive oil and a drizzle of cream, if you like, and/or a little crumbled soft cheese or a plant-based alternative.