Fry the duck liver briefly in a very hot frying pan with 1 tbsp. clarified butter. Remove, baste with maple syrup, season with salt and pepper and cool. Then finely mash with a hand blender and spread through a sieve. Slowly fold in the softened butter and egg yolks. This works very well with a hand mixer. Pour the mixture into a mold, cover with a lid and poach in a constant 80 °C water bath for about 20 minutes. Afterwards cool down.
Remove the skin from the onion, cut into strips and sauté in a frying pan with 1 tbsp. clarified butter. Season with salt and 1 tsp. brown sugar, extinguish with vinegar and currant juice. Simmer on low heat until the liquid has boiled away.
Peel and core the apple and cut into pieces. Fry in a frying pan with butter, sprinkle with 1 tsp brown sugar and caramelize.
Cut the duck liver mousse and bring to the table with the onions and apples.
Our tip: Use high-quality red wine for an especially fine taste!