Bringing the stove to medium-high, bring the mixture to a boil and continue heating until the sugar dissolves.
During this process, use a utensil similar to a potato masher to mash the plums, breaking them down.
Add lemon juice and stir to combine.
1 ½ tablespoons Fresh Lemon Juice
Lower the heat to a simmer and keep stirring while boiling, skimming off any foam.
Continue stirring for about 20-30 minutes total. You’ll know that the jam is ready when the juices have thickened significantly.
You can also test whether your jam is ready by using a cold plate! To do this, add a small plate to the freezer and place a spoonful of jam on the plate. If your jam sets within one minute on the cold plate you’re finished! If not, you’ll need to continue cooking a bit longer.
Finally, strain using a fine-mesh sieve discarding the cardamom pods and into an airtight heat-proof container and allow to cool before using.
Notes
After making your jam, you'll want to store it in the refrigerator and use it within one month!