Keep stirring on a low to medium flame until all the sugar dissolves.
Bring the mixture to a full boil, then reduce to low heat and cook for about 25 minutes stirring often.
Test the readiness of the jam with a spoon. If the mixture drops off the spoon easily, then let it cook for a few more minutes. The jam is ready when the mixture doesn't fall off the spoon easily and is lumpy.
At this point, you can use a stick blender to smooth the jam or leave it as is if you prefer chunks.
Once done, transfer the jam into sterilized jars and let it cool completely. Cover and refrigerate.