Cook the asparagus (there can be leftovers or asparagus fragments) until soft for about 8-10 minutes. Finely chop with the mixer.
Mix the mixture with the preserving sugar and the pulp of the vanilla pod. Bring the whole thing to the boil and then let it simmer for 4 minutes. After 3 minutes add the sherry, stir in and let simmer.
Rinse the jam jars and lids with boiling water. Pour the hot mass into the jars, close immediately and place on the lid for 5 minutes, then turn over.
The jam lasts for about a year. It goes well with boiled ham on bread.