Peel and wash the carrots. Cut out small strips of carrots with a knife from top to bottom at a distance of 1/2 centimetre all around. Cut the carrots into slices. Clean and wash the celery and keep the green, cut the celery into diagonal slices.
Wash duck breasts, dab dry and cut into slices of one centimetre thick. Heat the oil. Fry the duck breasts in it in portions until crispy brown, season with salt and pepper and remove from the pan.
Add carrots and celery slices to the frying fat and sauté. Drain the pineapple and collect the juice. Deglaze the vegetables with the Chinese sauce and 2/3 of the pineapple juice, bring to the boil and simmer for five minutes.
Stir the starch and remaining pineapple juice until smooth, stir into the sauce and bring to the boil again. Halve the pineapple slices, add to the vegetables with the duck breast and warm up. Season the duck slices to taste and serve garnished with the celery green.
Basmati rice tastes good with it.