For the caramelised onions:
1 tbsp vegetable oil
2 large onions, thinly sliced
For the patty melts:
1⁄4 small onion, finely chopped
500g beef mince
1 tbsp ketchup
Salt and black pepper
1 tbsp vegetable oil 8 slices rye bread
120g mature Cheddar, thinly sliced
120g Emmenthal, thinly sliced
3 tbsp mayonnaise
- Melt the butter with the oil in a pan over a low heat. Add the onions and cook for 35-40 minutes until deep golden brown and very soft, adding a splash of water as needed to prevent them from sticking. Set aside.
- In a bowl, mix together the onion, beef, mince, ketchup and some salt and pepper until just combined; do not overmix.
- Divide the mixture into four portions. Gently press each portion between two sheets of parchment paper until about 1⁄2cm thick.
- Heat the oil in a large heavy pan over a medium-high heat. Working in two batches, cook the patties for 2-3 minutes per side until nicely browned but still pink in the centre, pressing down gently with the back of a spatula. Transfer to a plate.
- Carefully wipe out the pan with a ball of kitchen paper and turn the heat to medium. Top four of the slices of bread with Cheddar, then add the beef patties, some caramelised onions and the Emmenthal. Sandwich together with the remaining bread slices and spread the tops with mayonnaise.
- Place in the pan, mayonnaise side down.
- Add a heavy-based pan on top to weight the sandwiches down. Cook for three minutes until the bottoms are golden brown. Remove the pan on top and spread the top of each sandwich with mayonnaise.
- Carefully flip them over, weight them again and cook for another 2-3 minutes until the second side is golden brown and the cheese is melted. Use cocktail sticks to secure a gherkin on top of each sandwich, then serve with skinny chips.
Per Serving: 723kcals, 38g fat (14.8g saturated), 38.9g carbs (6.5g sugars), 52.9g protein, 5.3g fibre, 0.738g sodium