Skin the calf’s liver well, remove any strands and cut into larger strips. Season the liver strips all over with salt and pepper and dust one side with flour. Heat the lard or oil in a pan, fry the liver quickly all around over high heat, lift out of the pan and keep warm.
Now pour off the excess fat from the pan and replace it with fresh butter, letting it foam up briefly. Lightly sauté the finely chopped onions in it, dust with about 1 tablespoon of flour and deglaze with beef broth.
In the meantime, finely chop the capers and add to the sauce together with the grated lemon peel, stir briefly and then add the whipped cream. Boil vigorously for a few minutes, season with lemon juice, add the liver strips again and reduce heat. The liver should only be in the sauce for a short time. If desired, the liver fillets can be garnished with fried bacon strips. As side dishes we recommend green beans, grilled tomatoes and potato rösti.