Cut the meat into bite-sized pieces. Peel and quarter the onions. Peel and chop the garlic cloves. Finely grind allspice, juniper berries and cloves in a mortar. Mix the meat with the ground spices, salt, pepper, tomato paste, cranberries, bay leaves and rosemary sprig well. Season well. Put everything in the soaked Römertopf.
Pour the port wine and beef stock over it and place the saucepan in the cold oven. Set to 200 degrees top / bottom heat and let the meat cook for about 2.5 hours.
The sauce is very thin, so thicken it with a little cornstarch mixed with water.
It goes well with dumplings, noodles or fried polenta.