American patty melts

Method

1. Heat 2 tbsp of the olive oil in a large non-stick frying pan over a medium heat. Add the onions, sugar and some salt and pepper, then fry, stirring often, until soft and nicely caramelised (15-20 minutes). Spoon into a bowl, then wipe the pan clean. 
2. Meanwhile, mix the beef mince with plenty of sea salt and freshly ground black pepper. Divide the mixture into 4 and shape each piece into a thin square patty that is slightly longer and wider than the bread slices. Set aside. 
3. Heat the remaining 2 tbsp olive oil in the frying pan and increase the heat to high. Add 2 of the patties and fry for 2-3 minutes on each side until nicely browned on the outside and cooked to your liking. I like them slightly pink in the centre as they’re juicier like this. Lift onto a plate and repeat with the remaining patties. Wash the pan clean and return it to a low-medium heat for 2-3 minutes. 
4. Meanwhile, butter one side of each slice of bread. Put 4 of the slices, buttered-side down, on a work surface and top each one with some of the onions, a slice of cheese, then a beef patty. Top the patty with another slice of cheese and the remaining onions. Top each stack with the remaining slices of bread, butter side facing up. 
5. Put 2 of the sandwiches into the hot pan and weigh them down with another frying pan. Cook for 3-4 minutes until crisp and golden, then flip them over and repeat. Slide onto a chopping board, then repeat with the other 2 sandwiches. Cut in half and serve with the dill pickles.