Berlin-Style Calf Liver with Apples and Golden Onions

Slice the onions into half-rings about 3–4 mm thick. Cut the washed apples, with skin but without cores, into wedges about 1 cm thick. Prepare two skillets about 26–28 cm in diameter and an ovenproof serving dish. Heat the oven to 80°C to keep the accompaniments warm briefly. Leave the liver in the refrigerator until ready to fry.

Heat 10 g of oil and 15 g of butter in the first skillet. Add all the onions and 1 g of salt. Cook over medium-low heat for about 15–20 minutes, stirring regularly, until the onions soften and turn golden brown. Reduce the heat if they darken too quickly. Transfer the cooked onions to the serving dish, leaving the fat and browned juices in the skillet.

During the last few minutes of cooking the onions, melt 15 g of butter in the second skillet. Add the apples and cook over medium heat for about 6–8 minutes, turning gently, until lightly browned and softened but still holding their shape. Add them to the onions in the serving dish. Cover loosely and place in the warm oven while you fry the liver, about 10 minutes. Keep the fat and juices in the second skillet as well.

Pat the liver dry with paper towels. The slices should be an even thickness of about 1 cm; remove any remaining tough membranes or ducts. Sprinkle the measured 10 g of flour thinly over both sides of the slices and pat it on gently, without forming a thick coating. Do not dredge them in additional flour. Use clean dishes and utensils for the cooked accompaniments and meat, separate from those used for the raw liver.

Add 5 g of oil and 5 g of butter to each reserved skillet, using the fat left from cooking the accompaniments. Heat over medium heat, but do not let the fat smoke. Place two liver slices in each skillet, without overlapping. Fry for about 4 minutes on one side, then turn and fry for about 4 minutes on the other. Reduce the heat if they brown too quickly. Cook slices of this thickness all the way through, without leaving the center raw; thicker slices need longer cooking over gentler heat. Season the cooked liver with the remaining 4 g of salt and all the pepper, then transfer to the serving dish with the accompaniments.

Carefully pour 25 ml of water into each hot skillet. Cook for about 1–2 minutes, stirring and scraping up the browned juices from the bottom with a wooden spatula. Do not pour off the fat. Combine both pan sauces and pour over all the liver, onions, and apples. Include any juices that have collected in the serving dish while the accompaniments were kept warm briefly.

For each portion, serve one slice of liver with a quarter of the apples, onions, and sauce. Serve immediately, without further prolonged heating, which dries out the liver. The recipe does not include additional potatoes, bread, or a decorative portion of butter.