Pea and watercress soup

Method

1. Heat the oil and butter in a large pan, add the onion and garlic and cook gently for 5 minutes, until beginning to soften. Add the potato and toss with the onion and garlic, then pour in the stock. Bring to the boil and simmer for 15 minutes, until the potato is tender.
2. Add the frozen peas and simmer for 3 minutes. Add the watercress and stir in until wilted. Remove from the heat, cool for a few minutes then blend with a hand-held blender (or in a food processor, in batches), until smooth. Return to the pan, season to taste with salt and freshly ground black pepper and keep warm over a gentle heat.
3. Meanwhile, preheat the grill to high. Grill the pancetta for 2-3 minutes each side, until crisp. Remove and drain on kitchen paper. Break up into pieces.
4. Ladle the soup into bowls and top each with some pancetta pieces.