Small bunch of Swiss chard
2tbs extra-virgin olive oil
1tbs sunflower or vegetable oil
8 x 70-80g pieces of calves' liver
250ml balsamic vinegar
3tbs pine nuts, toasted
3tbs sultanas, soaked in warm water
Salt and pepper
Preheat the oven to 220˚C, gas 7. Remove the leaves from the chard stalks. Blanch the stalks in boiling, salted water until just tender (about three to four minutes), drain and pat dry (this is important as you are going to put it into oil later). Put the leaves into the water for about a minute, drain and pat dry. Cut the stalks into thin batons.
Put the chard leaves and stalks into a pan with the olive oil. Turn the heat to low and gently warm these up.
Heat an ovenproof sauté pan until medium-hot, then add the sunflower or vegetable oil and put in the liver. Seal until crusty on both sides - taking care not to get the pan too hot or the liver might burn. Season.
Turn down the heat, add half the butter and put the pan into the oven for a minute or so, depending on the thickness and how you like your liver cooked (in the restaurant, we serve it medium-rare).
Take out of the oven, lift the liver out on to a warm plate, drain off the butter, add the balsamic vinegar to the pan and reduce by half, or until you have a syrupy consistency. Beat in the rest of the butter, add the pine nuts and drained sultanas, then turn the heat down and put the liver back in.
Spoon the chard on to your warmed plates, place the liver on top and drizzle with the sauce.