The best leek & potato soup

Preheat the oven to 200ºC, gas mark 6. Wash and trim the leeks, removing any papery outer layers and any mud or grit. Cut 2 leeks in half lengthways, then drizzle ½ tbsp olive oil onto a baking tray, arrange the leeks cut-side down, then roast for 20 minutes.

Remove the leeks from the oven and carefully flip, so the cutsides (now slightly browned) are facing up. Mix 1 tsp miso paste with 1 tbsp water, then coat the leeks and return to the oven for 10 minutes more.

Finely slice the remaining leeks. Melt the butter and remaining oil in a large saucepan or casserole over a medium-low heat and add the leeks and black pepper. Cook for 15-20 minutes, stirring often, allowing the leeks to soften and take on a sweet aroma. Try not to let them take on any colour. Meanwhile, peel and quarter the potatoes, or cut into chunks if they are big.

Remove a third of the leeks and set aside. Add the remaining miso to the saucepan and stir well. Add the potatoes, pour in the stock and add the bay leaf. Bring to the boil, then simmer, covered with a lid, for 15-20 minutes, or until the potatoes are fork-tender and falling apart.

Remove the bay leaf, add the cream, then blitz the soup using a handheld blender, or leave to cool, then blend in a stand blender. I leave a few small pieces of potato for texture, but blitz until smooth if you prefer. Fold the reserved softened leeks into the soup, then season to taste.

Cut the roasted leeks into thirds, discarding the papery outer layer if too dried out. Divide the soup between 4 bowls, top each with a drizzle of extra virgin olive oil, the roasted leeks and a sprinkle of chopped chives, then serve.