Creamy butter bean, kale & lasagne soup

Make this hearty, wholesome soup on cold winter days. Enriched with egg yolk and parmesan lends it a velvety texture reminiscent of carbonara

Heat the oil in a large saucepan. Add the pancetta and sizzle for a few minutes until crisp in places. Stir in the onion and thyme, cook for 8-10 mins until the onion softens and starts to caramelise.
Add the kale stalks and garlic, stir for a minute, then add the butter beans along with their liquid, the stock cube, 800ml water and parmesan rind. Snap the lasagne sheets into smaller pieces and add to the pan. Season well, stir and cover with a lid. Cook for 8 mins over a low heat, stirring every now and then to prevent the pasta sheets from sticking together.
Meanwhile, whisk the egg yolks and grated parmesan together in a bowl. When the pasta has softened but still has a little bite, add the kale leaves and a splash of water if needed – the consistency should be soupy. Cook for 5 mins, until the pasta and kale are cooked, then stir in the egg yolk mixture, lemon zest and a squeeze of juice. Stir constantly over a low heat to prevent the egg from curdling (it should thicken and enrich the sauce). Ladle into bowls and top with a little more parmesan, a drizzle of good extra virgin olive oil and a twist of pepper or pinch of chilli flakes, if you like. Serve with crusty bread for dipping.