Soak the Roman pot for 30 minutes. Meanwhile, cut the tomatoes in half, cut the cucumber into eighths and wash the meat and pat dry. Pluck the cabbage into the Roman pot, add the mustard seeds, bay leaves and juniper berries and place the meat in the middle.
Using a sharp filleting knife, make small cracks in the meat and lard the cloves. Position the tomatoes and cucumbers.
Put the lid on the Römertopf and put top and bottom heat in the non-preheated oven at 225 ° C and cook for 1.5 hours.
Remove the lid and brown the Kasseler for 10-15 minutes at 225 ° C.