Peel and finely chop the onion. Peel, wash and finely dice the carrots. Wash the rosemary, shake dry, pluck a few needles from the stems. Wash 1 orange thoroughly, grate dry, peel as julienne. Wash the flesh, dab dry, cut the skin into a diamond shape. Cut oranges in half, squeeze juice
Heat oil in a pot, sauté onion, add lentils, add 500 ml broth, bring to the boil, cover and cook for 35-40 minutes. After about half the cooking time add the carrots
Place meat in 2 portions in a coated pan without fat, skin side down, heat pan, fry skin side well. Season meat side with salt and pepper. Spread rosemary and orange peel on top, also in 2 portions. Turn and fry for about 1 minute. Place the duck breasts on a baking tray. Cook in a preheated oven (electric cooker: 150 °C/ convection oven: 125 °C/ gas: see manufacturer) for approx. 15 minutes
Use frying fat for other purposes, except for 1 tablespoon. Deglaze frying set with orange juice and 150 ml stock and bring to the boil. Stir starch and 3 tbsp. water until smooth. Stir into the boiling liquid, bring to the boil and simmer for about 1 minute. Season to taste with salt, pepper and sugar. In the meantime knead dumpling dough in a bowl. Form a roll from the mixture (approx. 24 cm long) and cut into 12 slices. Form thalers with your hands and roll them into almond flakes. Press lightly
Heat clarified butter over medium heat in 2 portions in a coated pan. Fry about 6 potato thalers on each side until golden brown. Keep warm. Process the remaining thalers in the same way
Wash parsley, shake dry and chop finely. Season lentils with vinegar, salt, pepper and sugar. Heat the sauce again. Remove meat from the oven and wrap in foil. Let it rest for 3-4 minutes. Cut open duck breasts and arrange on plates with lentils, sauce and potato taler. Sprinkle lentils with parsley. Garnish each plate with a slice of orange