Cut the meat into larger pieces. Peel and quarter the onions. Put both in a larger saucepan and pour vinegar and water over them. Add all the spices, sugar, salt and pepper. Press the juniper berries down a little beforehand. Then bring everything to the boil 1 x and stir the brew. Then season to taste. It should be very sour, but still come through with a slight sweetness. Possibly add a little vinegar and sugar to season. Then reduce the heat halfway and let everything simmer gently for approx. 1 hour 40 minutes with the saucepan closed. After this lapse of time, try the meat. It should be soft. Otherwise, increase the cooking time by 5 - 10 minutes.
When it is done, lift it out of the brew with a slotted spoon and store it briefly. Then pour the brew through a sieve and fish out the soft (now fallen apart) onions. Now layer the meat and onions in any shape (I like to use aluminum loaf tins that can be used again and again - actually for meat loaf).
Soak the gelatine in cold water and let it swell. Heat 500 ml of the cooking stock again a little (do not boil), dissolve the swollen gelatine in it while stirring vigorously and then pour it over the meat. It should be completely covered. First let everything cool down at room temperature and then put in the refrigerator for at least 5 hours. But it tastes best when it has at least 2 days to really soak in the refrigerator.
We had tartar sauce and fried potatoes ................ The link for tartar sauce here: tartar sauce