Wash and core the yellow plums - then dice. Peel and finely dice the onions and garlic cloves.
Rub the peel of the limes and then squeeze out the juice.
Put all ingredients in a large saucepan and bring to a boil. Turn down the heat and reduce to a low heat. This can take up to 3 hours. Stir regularly, stirring frequently at the end. There is a risk that it will burn.
Fill into jars while still hot and close immediately. Let cool standing on the lid.
The plum kernels can be prepared for a liqueur according to the Herta recipe.