Veal is one of the most subtle and expensive offals you can buy and that subtlety is all important for this saute. Seared calves’ liver, still pink and juicy in the middle, is vastly superior to any other animal’s liver. Lambs’ liver, for example, just will not do.
Calves’ liver comes almost exclusively from box-reared animals, and you have to decide for yourself whether or not this is a moral issue. It is worth seeking out an organic butcher and finding out whether there is any alternative and kinder method of veal production, but most of what is available comes from Holland where darkened, boxed living conditions are standard. Even so, obtaining calves’ liver is not easy outside London.
The first time you cook this dish, I suggest you do so for two rather than four people – in which case halve the quantities. There will seem to be a lot of onions when you first start out, but they cook down to a fraction of the original bulk as the water evaporates from them.
Mise en place
At least 2 hours ahead, prepare the Melted Onions: slice the onions into thin rings. Melt 55g/2oz of the butter in the casserole over a low heat. Stir in the onions and bay leaf. It is important not to allow the butter to brown – you’re making a white compote, not caramelised onions, which are a different dish altogether.
Put on the lid and cook, covered, over a very low heat for 30 minutes, by which time the onions will have started to collapse. Remove the lid and stir thoroughly. Cover again and continue to cook for 1 hour.
Remove the bay leaf and add the vinegar and sugar. Season with salt and pepper. Stir and turn up the heat to medium. Cook to evaporate the liquid stirring while you do so. Stop cooking before the onions take on colour. Keep warm for immediate use, or store in a closed container in the fridge for up to 1 week.
Prepare the liver: carefully remove any tubes or threads from the liver. Put the flour on a plate and season well. Coat the pieces of liver in the seasoned flour and shake off any excess.
Heat the saute pan over a medium heat. Put a tablespoon of sunflower oil in the pan with a nob of butter and gently lay the slices of liver in this. Cook for 2 minutes then turn. Scatter over the sage leaves and cook for 60 seconds more.
Arrange beds of the warm onion compote on 4 warmed plates, place the cooked liver slices on top of them and keep warm.
Turn up the heat under the pan and deglaze it with the wine or vinegar, scraping and stirring. Add 2 tablespoons of chicken stock and bubble before swirling in a nob of butter to finish the sauce. Pour over the liver and serve immediately.
450g / 1lb calves’ liver cut into 4 thin slices
4 tbsp flour
1 tbsp sunflower oil
55g / 2oz butter
4 large sage leaves
5 tbsp dry white wine, or 2 tbsp basalmic or sherry vinegar
2 tbsp Chicken Stock
Salt and pepper
FOR THE MELTED ONIONS
8 large onions
85g / 3oz butter
2 tbsp white wine vinegar
1 tbsp caster sugar
heavy casserole dish with lid
saute pan large enough to hold all the liver (or 2 saute pans).