Thyme infused broad bean soup with crispy smoked pancetta

• 20 g/¾ oz/1 generous tbsp butter 
• 1 tbsp extra-virgin olive oil, plus an extra splash for frying
• 150 g/5½ oz smoked pancetta, finely chopped 
• 1 onion, finely chopped 
• 1 celery stalk, finely chopped 
• 1 garlic clove, finely chopped 
• A handful of thyme leaves, plus a few to garnish 
• 350 g/12 oz/2¾ cups frozen broad (fava) beans 
• 1 large potato (about 200 g/7 oz), chopped into small cubes 
• 1 litre/35 fl oz/4⅓ cups vegetable stock (bouillon)

Preparation:

Heat the butter and olive oil in a large, heavy-based saucepan set over a medium–high heat. Add a third of the pancetta, and all the onion, celery, garlic and thyme, and sweat for 5 minutes. Stir in the broad beans and potato, then pour in the stock, and bring to the boil. Reduce the heat, cover with a lid and simmer for about 10–12 minutes, until the beans and potatoes are cooked. Remove from the heat and allow to cool a little. Meanwhile, add a splash of extra-virgin olive oil to a small frying pan (skillet) set over a medium heat. Add the remaining pancetta and stir-fry until nice and crispy. Set aside. Transfer the slightly cooled soup to a blender or food processor and blend until smooth (you may need to do this in 2 batches). Return it to the saucepan and gently reheat, if necessary. Divide among individual bowls, sprinkle with the crispy pancetta and garnish with thyme leaves to serve.