Method

• 1.
  Heat oil and 20g butter in a large heavy- based saucepan over medium-high heat. Add onion, leek, garlic and half of the pancetta. Cook, stirring frequently, for 3-4 minutes then add cauliflower and cook for a further 5-6 minutes or until cauliflower and pancetta begin to brown. Add stock, bring to the boil, reduce heat to low and simmer, stirring occasionally, for 1 hour or until vegetables are soft. Transfer soup to a blender (or use a stick blender) and whiz until smooth. Season and keep warm.
• 2.
  Meanwhile, add the remaining 70g pancetta to a small, non-stick frypan and cook over high heat, stirring frequently, for 4-6 minutes until golden and crisp. Drain on paper towel and set aside.
• 3.
  Place remaining 40g butter in a medium frypan over high heat. When butter begins to foam, add sage. Cook, stirring continuously, for 1-2 minutes until sage is crisp and butter is golden brown.
• 4.
  Divide soup among bowls. Drizzle with brown butter and top with crispy pancetta and fried sage. Scatter over parmesan and freshly ground black pepper to serve.