Heat 2 tsp of the olive oil and the butter in a frying pan over a medium heat, add the chopped onion and sauté for 4 minutes, stirring frequently. Remove from the heat and set aside in a large bowl to cool.
Once the onion is cooled, add the mince and finely chopped bacon, then season with salt and freshly ground black pepper. Mix well so that everything is evenly combined and then divide the mixture to form 4 burgers. Place the burgers on a plate and refrigerate until you’re ready to cook them. Remove them from the fridge at least 30 minutes before you’re ready to cook.
When you’re ready to cook the burgers, heat 3 tsp of the olive oil in a large frying pan or grill pan (we use our Le Creuset grill pan) over a high heat. If you like your buns toasted, place each half face down in the hot pan and let them toast to your liking – make sure they don’t burn. Remove and set aside while you cook the burgers.
Now place the burgers in the pan and cook for 2.5 minutes on each side. If you’re adding cheese, and like it melted, top each burger with the slice(s) of cheese once the burgers have been turned and cooked on the other side for 1.5 minutes. Then, place a large stainless steel bowl (if using a frying pan) or rectangular roasting tin (if using a grill pan) over the burgers for the final minute of cooking – this will melt the cheese by providing a steaming environment.
Finally, assemble your burger with any additional toppings and/or sauces (see Notes)
Enjoy with dirty fries or chunky oven chips on the side!