Wash the turkey and pat dry. Rub the outside of the turkey with butter and season with salt and pepper. Also distribute the butter between the breast and the skin.
Quarter the apples. Quarter the lemon. Stuff the turkey with apples, thyme and lemon.
Cook the turkey in the oven at 200 ° C for 30 minutes.
Quarter the onions. Cut the carrot, celery and leek into small pieces and fry with the onions, deglaze with wine, let the alcohol boil off and fill up with a little broth.
Take the turkey out of the oven, brush with melted butter, add the stock with vegetables and leave everything in the oven for at least 3 hours at 140 ° C.
For the vegetables, dice the onions, clean the red cabbage and cut into small pieces.
Braise the onion in 1 tablespoon of butter. Add the red cabbage, cook for 5 minutes and season with salt and pepper. Add the bay leaf, juniper berries and vegetable stock. Cover and cook the red cabbage for 20 minutes.
Mix the cornstarch with red wine vinegar, add to the red cabbage and bring to the boil while stirring.
Take the turkey out of the roaster and place it on a tray for half an hour at 160 ° C in the oven. Puree the gravy that has accumulated in the roaster with the soft vegetables to create a sauce. Season this with salt and pepper.
Cook the bread dumplings according to the instructions on the package.
Take the turkey out of the oven, let it rest for 20 minutes, carve it and serve with the apples, dumplings and the sauce.