Add 3 tbsp of the oil to a casserole and pre-heat over medium-low heat. Finely dice the onion and add to the casserole. Cut the leaves off the Swiss chard. Roughly chop the leaves and set aside, then finely dice the stems. Add the stems to the onion and continue cooking until both have softened.

In the meantime, trim and discard the lower stems of the coriander and roughly chop the rest. Dice the potatoes into 1cm pieces and give the lentils a quick rinse under the tap. When the onions and stems are soft, stir in the cumin and black pepper to heat it through, then tip the lentils into the pan along with the potatoes, coriander and 1.5l of water. Bring to a boil, reduce the heat and simmer covered for 20 minutes or until the lentils are tender.

Add the chard leaves and salt and simmer for another 10 minutes until the lentils and potatoes are fully cooked.

Meanwhile, measure out the lemon juice. Then peel and finely grate the garlic. Pre-heat the remaining 4 tbsp of olive oil in a small frying pan and sauté the garlic and dried mint until the garlic is golden. Add this to the soup along with the lemon juice. Turn off the heat, give it a stir, then divide over bowls and serve with a generous drizzle of extra virgin olive oil and some bread.