Clean and wash the Brussels sprouts and steam them in a little salted water for 20-25 minutes. In the meantime, wash duck breasts and pat them dry. Heat the oil in a pan and fry the duck breasts on each side for 12-15 minutes at medium heat.
Season with salt and pepper. Cook spaetzle in boiling salted water for about 15 minutes. Remove duck breasts from the pan and let them rest. Drain frying fat, except for 1-2 tablespoons. Deglaze remaining frying fat with stock and bring to the boil.
Bind with sauce thickener. Season to taste with salt, pepper and jelly. Heat half of the butter in a small pan. Add breadcrumbs, mix and roast over medium heat until golden brown. Drain the sprouts and let them drain.
Heat the rest of the butter until it is frothy and drizzle over the Brussels sprouts. Cut duck breasts into slices and arrange on plates together with Brussels sprouts, spaetzle and breadcrumbs. Garnish with parsley as desired and serve.