Spiced leek broth

In a large pan, heat the oil over a medium-high heat, then fry the leeks, carrots and cumin seeds with a pinch of salt for 10 minutes, stirring often, until softened and lightly caramelised. Add the garlic and fry for 2 minutes, then add the tomato purée and fry for another 2 minutes.

Add the stock and cinnamon stick, then tie the coriander stalks into a bundle with cooking string and add them too. Bring to a simmer and cook gently for 10-12 minutes, until the veg are tender.

Season the broth, adding the lemon juice to taste – it should be gently acidic. Remove the cinnamon stick and coriander stalks, then divide the broth among bowls and top each with a dollop of yogurt, a scattering of toasted walnuts and coriander leaves, some red pepper flakes and a drizzle of oil.