combine in a small pot and heat on medium until everything breaks down, smooshing the berries to your desired mooshiness
bring to a rolling boil for 15 minutes, stirring continuously
splatter a drop onto a small plate and let cool to see if it's got a bit of a skin on it, and if it does, it's done!
this is a pretty small serving, just one jar, so if you are going to eat it all pretty quickly, you can just put it in a clean jar and keep it in the fridge