For the plum-poppy seed jam, halve plums, remove seeds and cut into small pieces, puree with a hand blender and mix with the preserving sugar. Cover and let stand overnight.
Heat fruit puree, bring to a boil and boil for 4 minutes until bubbly, add poppy seeds and lemon juice and boil for 1 minute more.
Pour plum-poppy seed jam into jars with screw tops and seal tightly immediately.
Preparation Tip:
Try the plum-poppy seed jam as a filling or with cheese or game.