Chop plum and jamun into small pieces. Remove the seeds.

Take a small bowl filled with water, add 1 tbsp lemon seeds in it and leave it overnight. They will have formed a gel by morning. Strain out the excess water and add this gel ready.

Take a big pan, add chopped plum and jamuns with sugar in it. Mix well and keep the pan closed for 2 hours. The fruits would have started leaving the juices.

Transfer this content into heavy bottom pan, add grated ginger and keep it for boiling on medium flame. Keep stirring and boil for 3-4 minutes.

Remove from the flame and mash the fruits using a potato masher or ladle.

Now again keep it for boiling on low flame for 5 minutes. Keep stirring.

Add lemon juice and gel from lemon seeds and mix well. It will start combining and check the setting point. (Check my notes above)

If the jam has set, remove from flame.

Transfer the warm jam in sterilized containers and keep it sealed.

Once container opened or used, refrigerate it.