For the caramelised onions:
1 large red onion, thinly sliced
1 tbsp butter
1 tbsp olive oil
250ml red wine
1 tbsp red wine vinegar
1 tbsp sugar
Salt and black pepper
For the burgers:
700g beef mince
2 tsp Worcestershire sauce
120g creamy blue cheese, crumbled
4 ciabattas, split
8 crispy streaky bacon rashers
- Melt the butter and oil together in a large pan over a medium heat. Add the red onions and sprinkle with salt.
- Cook for about five minutes until the onion is soft and the pan begins to dry out. Add the wine and allow to bubble, using a wooden spoon to scrape any sticky bits from the bottom of the pan. Turn the heat to low and cook for another 15 minutes. Whenever the pan gets dry, add a splash of water.
- Add the vinegar and sugar and cook for another five minutes. The pan should be dry.
- Transfer the onions to a bowl and set aside.
- Place the beef mince in a large bowl. Add the Worcestershire sauce, a teaspoon of salt, and half a teaspoon of black pepper. Mix gently with your hands until just combined.
- Wet your hands and shape the meat into eight equal patties around 1cm thick. Make a slight indentation in the centre of four of the patties to hold the cheese. Divide the blue cheese into four equal portions, shape into discs, and set a disc in each of the indentations.
- Top the cheese with the remaining patties and gently but firmly seal the edges to encase the cheese. Place in the fridge for at least 30 minutes and up to 4 hours.
- Cook the burgers on a hot grill, frying pan or barbecue until cooked to your liking. Place a burger in each of the four ciabattas and top each with two crispy streak rashers, some caramelised onions and a handful of rocket.
Per serving: 946kcals, 39.5g fat (36.6g saturated), 51.9g carbs, 7.4g sugars, 79.6g protein, 2.7g fibre, 2.046g sodium
MAKE IT YOURS: If you’re not a fan of blue cheese, you can substitute it with any good melting cheese you like! We like Mozzarella, Gruyère, goat’s cheese or mature Cheddar.