Preheat the oven to 80 ° C top and bottom heat and place a roasting plate on the middle rack.
Carefully cut the skin side of the duck breasts at an angle several times with a sharp knife, so that the dark flesh is not damaged. Season the meat evenly on both sides with salt and pepper. Massage the spices into the cuts.
Let the oil get hot in a pan and fry the duck breasts with the skin side down on the highest heat (switch to 9 for me) for 3 minutes. Turn breasts and fry for another 2 minutes at 2/3 heat (switch on 6). Then take the duck breasts out of the pan and let them rest on the plate in the oven for 30 minutes. Then the breasts are just pink.
In the meantime, pour off the fried fat. Deglaze the roast with the sour cherry juice and port wine. Top up with the poultry stock. Loosen the roast set from the bottom by stirring with the wooden spoon. Reduce the sauce to the desired consistency and add the cherries. Season to taste with lemon, sugar, pepper and salt. Possibly bind with cold flakes of butter.
Cut open the duck breasts and serve with the sauce.