- 70g/2½oz fresh white breadcrumbs
- 2 tbsp whole milk
- 500g/1lb 2oz beef mince
- 1 garlic clove, crushed
- 1 tbsp tomato purée
- 1 tbsp Worcestershire sauce
- 2 tbsp chopped flatleaf parsley leaves
- 12 thin slices round pancetta
- salt and freshly ground black pepper
- 150g/5½oz mayonnaise
- 1 tsp Dijon mustard
- 1 tbsp chopped fresh tarragon leaves
- 6 ciabatta or crusty bread rolls, halved
- 60g/2¼oz spinach leaves
- 150g/5½oz caramelised onion relish, from a jar
- 150g/5½oz mature Cheddar, thinly sliced
- 6 gherkins, thinly sliced
- Put the breadcrumbs and milk in a bowl, mix and set aside for 5 minutes, or until the milk is absorbed. Add the mince, garlic, tomato purée, Worcestershire sauce and parsley, season with salt and pepper and mix well.
- Shape the mixture into six large, flat patties. Place a slice of pancetta on both sides of each patty. Heat a large frying pan over a high heat. Add the patties and cook, in batches, for 4 minutes on each side, or until the pancetta is cooked and the burgers are done to your liking.
- For the tarragon mayonnaise, put the mayonnaise, mustard and tarragon in a bowl and mix. Set aside.
- Preheat the grill to high, then toast the rolls. Spread them with the tarragon mayonnaise and top with the spinach, patties, caramelised onion rellish and Cheddar. Serve with the gherkins.