Pierce the plums several times with a needle. Bring the plums, vinegar, sugar and garlic to the boil in a saucepan, cover and cook for about 5 minutes.
In the meantime, cut the herbs roughly.
Pour the plums into sterilized jars while piping hot and place the herb mixture between them. Close the jars immediately and turn them upside down. Cover with a cloth and let cool down slowly.
Let the plums stand in a cool, dark place for at least 2 weeks.
They can be kept for at least 6 months. Good accompaniment to boiled meat, roast pork or poultry.