White Bean, Kale & Parmesan Soup

Warm the olive oil in a 5–6 litre pot over medium-low heat. Add onion, carrot, and celery with a pinch of salt and cook gently 10–12 minutes, stirring now and then, until soft and sweet but not browned. Add garlic, pepper flakes, and the rosemary sprigs and cook 1–2 minutes until the garlic turns pale gold at the edges.

Add beans, Parmesan rind, and stock. Bring to a boil, then reduce to a low simmer and cook uncovered 25–30 minutes, stirring the bottom occasionally so the softened rind doesn't stick. Fish out the rosemary stems. Scoop about 2 cups of beans and liquid into a bowl, mash smooth with a fork or blitz with an immersion blender, and stir back in to thicken the body.

Stir in the kale and simmer 5–8 minutes until tender. Remove the rind (chop any soft parts and return them). Off the heat, add lemon juice and half the grated Parmesan; season with salt and plenty of pepper. Serve with the rest of the cheese and a thread of olive oil. To freeze: cool quickly in shallow containers, refrigerate within 2 hours, and freeze up to 3 months; the soup thickens on standing, so thin with water when reheating and refresh with lemon.