Cacio e pepe leek & potato soup

Finely slice about 150g leeks into rounds. Heat 1 tbsp oil in a large saucepan over a medium-high heat and add the leeks with a pinch of salt; cook for 5 minutes until golden, slightly crisp and caramelised. Transfer to a plate lined with kitchen paper. Roughly chop the rest of the leeks. Add the remaining ½ tbsp oil to the pan, lower the heat to medium and sweat the chopped leeks and shallot for 5 minutes, until golden and softened.

Meanwhile, scrub the potatoes, then cut into 1cm chunks. Once the leeks have softened, add the potatoes, bay leaf, stock and 350ml water with a pinch of salt. Cover, bring to the boil, then simmer for 15 minutes, or until the potatoes are tender.

Remove and discard the bay leaf, then transfer the soup to a blender and whizz until smooth (or use a stick blender in the pan). Pour the soup back into the pan, return to a medium heat to heat through, then stir in the cacio e pepe paste and season, adding more water if you want a looser consistency. Pour into bowls, then spoon some of the golden leeks over each bowl and finish with freshly ground black pepper. Serve with the crusty bread.