Wash the duck breast, dab dry and make a diamond-shaped incision in the skin. Wash the thyme, shake dry and pluck off the leaves, except for a little to garnish. Heat a large pan without fat, place the duck breasts in the hot pan with the skin side down and fry for about 5 minutes. Turn the duck breasts, season with salt and pepper and fry them from the meat side also until golden brown (3-5 minutes). In the meantime, heat apple jelly in a pot and stir in thyme leaves. Remove duck breasts from the pan briefly and season with salt and pepper on the meat side.
Drain the fat, put the duck breasts back into the pan and spread the apple and thyme jelly with a spoon on the skin side of the duck breasts. Pour on approx. 1/8 litre of hot water. Roast in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 10-15 minutes. Meanwhile clean, wash and cut the pointed cabbage into strips. Peel and finely chop the onion. Heat butter in a wide saucepan. Sauté onion in it. Add the pointed cabbage and braise for about 5 minutes, stirring occasionally. Season with salt, pepper and nutmeg. Let the finished duck breast rest for about 5 minutes, then cut into slices. Season stock with salt and pepper.
Heat butter in a wide saucepan. Sauté onion in it. Add the pointed cabbage and braise for about 5 minutes, stirring occasionally. Season with salt, pepper and nutmeg. Let the finished duck breast rest for about 5 minutes, then cut into slices. Season stock with salt and pepper. Arrange on plates with duck breast and pointed cabbage. Garnish with thyme