For the pumpkin jam, peel the pumpkin and remove (remove seeds and soft interior with a spoon). Cut the pumpkin flesh into pieces. Rinse oranges and lemons with hot water and rub dry. Cut into thin slices. Peel the ginger and grate finely.
Heat 1 l water in a pot, add pumpkin pieces, citrus slices, ginger and star anise fruit. Simmer for 30 minutes.
Stir in jelling sugar and simmer for about 20 minutes to make a puree. Test by dragging a wooden spoon handle across the bottom of the pot. If a trace remains visible, the jam is ready. Remove star anise.
Pour the pumpkin jam into prepared twist-off jars, drizzle a little alcohol over the top with an eyedropper, and light. Seal immediately and store the pumpkin jam in a cool, dark place.