Miltä maistuu buccaneer-kastike

Eikö kellään ole kokemusta?

110g/4oz chilled butter, cut into cubes

60g/2½oz shallots or small onions, peeled, thinly sliced

40g/1½oz fresh root ginger, peeled, finely grated

110g/4oz fully ripe bananas, peeled, sliced into rounds

6 tbsp raspberry vinegar

400ml/14fl oz veal stock

salt and freshly ground black pepper