place sweetener, fruit, and juice in a small pot.  bring to a boil and stir often. once boiling turn down a bit and stir cornstarch in a cup with aproximately 1/4 cup cold water then put mixture of cornstarch and water in the pot.  once the fruit is very soft and everything has been boiling for a little while turn off and pour jam into a jar. let cool for a few minutes then refrigerate.  let it thicken in the fridge for a few hours.

this is very good on toast. 

*if you use sweeter fruit you need less sweetener