Peel and finely chop the onion. Peel and finely dice the carrots. Warm a large pan over a medium heat. Add 1 tbsp oil, the onion and carrots with a good pinch of salt. Lower the heat. Sweat for 8-10 mins to start to soften the veg.

While the veg sweat, peel and chop the garlic. Dice the tomatoes. Add to the onion and carrot, along with 1/2 tsp harissa (or use more if you like things spicy). Let it cook till the tomatoes break down to a saucy paste, 5-10 mins. Crumble in the stock cube. Pour in 500ml boiling water. Swirl to mix and simmer for 5 mins.

Grate in the zest from the lime and mandarins, keeping a pinch back for garnishing. Squeeze in the juice. Taste and adjust seasoning as needed. Finely chop the parsley leaves and swirl them through the soup. Ladle into warm bowls and serve topped with the last of the zest.