1 Start with the caramelized onions. Fry the onions in the oil and butter over a gentle heat until transparent and soft (6 mins) then sprinkle on the salt and sugar and continue cooking, stirring from time to time until golden and sticky and beginning to crisp at the edges. Set aside.

2 Mix together all the burger ingredients and season. Mixing them with your hands makes it easier. Shape into 4 burgers about 10- 12 cm diameter.

3 Heat the grill to its hottest setting and cook the burgers for 3-4 mins on each side for rare, 4-5 mins for medium and 5-6 minutes for well done.

Pop the split ciabatta buns under the grill to warm a little.

Load up the buns with a handful of salad leaves, a couple of tomato slices, a burger, a tangle of onions and a dollop of blue cheese dressing for those who'd like it.