3 red onions, thinly sliced
300驳/10陆辞锄 plain flour
2 tbsp balsamic vinegar
salt and freshly ground black pepper
1 tbsp brown sugar
1 tbsp olive oil
70驳/2陆辞锄 salted butter, plus extra for greasing
200ml/7fl oz double cream
2 free-range eggs
100驳/3陆辞锄 feta
70驳/2陆辞锄 lard