Personally, Duck Liver terrines are my best dishes but I don't think you find fresh duck liver in the States so I will abstain from posting any recipes. As for Calf's liver this is my favourite - one calf’s liver sautéed in butter, cut up in slices, on a bed of caramelized onions and sautéed apple slices. Served obviously with a creamy potato purée, what else?! —Babette's Feast
Pre-heat the oven to 225 degrees F and put inside 2 bowls to warm up, the serving dish and 4 plates.
Peel the onions and slice them in a mandolin. Set aside.
Peel the apples, cut in quarters and remove core. Cut in slices. Set aside.
In a large sautée pan, melt 1.5 ounces of butter. Add the onions, mix, lower the heat and put a lid on top and sweat for 10 minutes. Remove lid and let caramelize for another 10 minutes without letting them burn. With a slotted spoon remove from the pan to one of the bowls in the oven and keep warm.
In the same pan, using the butter left over from the onions, add the slices of apple and cook 1 minute on each side. Gently remove them from the pan to the other bowl in the oven and keep warm.
In the same pan add the other 1.5 ounces of butter plus one tablespoon of olive oil. When it stops sizzling add the liver slices, brown 1 minute on each side. Remove to a cutting board and slice in thin strips. Put back in the pan, add the thyme leaves, season with salt and pepper and deglaze with the balsamic vinegar, mixing well until reduced. Put in warmed serving dish.
Garnish with a sprig of thyme and balsamic glaze all over.
Serve on warm plates with a Creamy Potato Purée (see recipe posted before).