Rachel Allen's Potato, Leek, and Smoked Bacon Soup

Ingredients (15)

• 1 tablespoon sunflower or olive oil
• 4 slices (rashers) bacon, diced
• 2 tablespoons (25g) butter
• 1 onion, coarsely chopped
• 1 large leek, trimmed and diced
• 2 large potatoes (about 1 pound/450g in total), peeled and diced
• Salt and freshly ground black pepper
• 5 cups (1.2L) chicken stock or vegetable stock
• Parsley Pesto:
• 1/2 ounce (15g) fresh flat-leaf parsley
• 1 clove garlic, coarsely chopped
• 1 tablespoon pine nuts, lightly toasted
• 1 tablespoon finely grated Parmesan cheese
• 4 tablespoons extra virgin olive oil, plus more if needed
• Salt and freshly ground black pepper