It's easy! Prepare rhubarb by trimming the stalks and slicing them into smaller chunks. Sprinkle with sugar and let sit for an hour. Then, add the mixture into a saucepan and simmer on medium heat until it starts boiling and the mixture thickens. Remove the foam as you go. To check if the jam is ready, use a spoon to create an open trail behind it as you stir. Or for more details and tips, check the recipe card for this strawberry rhubarb jam.