500g good calves’ liver, deveined and cut into strips
50g plain flour, seasoned
3 tbsp white wine vinegar
Polenta, to serve
Heat the olive oil and butter in a large, heavy-based frying pan over a medium heat. Add the onion and cook, stirring occasionally, for 6-8 minutes, until soft but not coloured. Remove with a slotted spoon.
Dust the liver in the seasoned flour, shaking off any excess. Add to the hot pan and sauté quickly, about 2-3 minutes, until browned but still tender. Stir in the white wine vinegar, then add the softened onions and some seasoning and toss everything together. Serve immediately, with some creamy polenta.