3 red onions, thinly sliced
300²µ/10Β½΄Η³ϊ plain flour
2 tbsp balsamic vinegar
salt and freshly ground black pepper
1 tbsp brown sugar
1 tbsp olive oil
70²µ/2Β½΄Η³ϊ salted butter, plus extra for greasing
200ml/7fl oz double cream
2 free-range eggs
100²µ/3Β½΄Η³ϊ feta
70²µ/2Β½΄Η³ϊ lard