30 g breadcrumbs
1 tbsp fresh rosemary, finely chopped
2 tbsp Worcestershire sauce
2 tbsp olive oil
1 tbsp butter
1 onion, thinly sliced
270 ml beef stock
1 tbsp ketchup
salt and black pepper
1 tbsp cornflour
1 In a mixing bowl, combine the minced beef with the breadcrumbs, rosemary and half of the Worcestershire sauce. Divide the meat into four and shape into equal patties.
2 Heat the olive oil and butter in a large frying pan over a medium-high heat. Add the burger patties and cook for 4-5 minutes on each side until cooked throughout.
3 Remove to a plate, cover with some tin foil and set aside until ready to use. Reduce the heat to medium-low, add the onions to the same pan and cook until they are translucent and soft.
4 Add all but a tablespoon of the stock along with the ketchup, remaining Worcestershire sauce, salt and pepper.
5 In a small bowl, whisk together the cornflour and remaining stock to make a thin paste. Whisk this into the onion sauce.
6 Bring the mixture to a boil, then reduce the heat to low. Add the burgers back into the pan along with any juices they’ve released onto the plate. Heat through for 2-3 minutes, then serve with mashed potatoes.