Gather all ingredients before starting the recipe.
Heat 1 tbsp olive oil in a medium sauce pan over medium high heat.
Add 2 whole yellow onions chopped and stir to combine. Cook for about 15 minutes, stirring once or twice.
When the onions begin to brown, reduce heat to medium and add 2 sprigs parsley, 1 sprig fresh rosemary, 2 whole bay leaves and stir to combine, cook for another 3 minutes.
Sprinkle 2/3 cup sugar over the mixture and cook, without stirring, until the sugar melts, about 5 minutes.
Stir to combine, increase heat to medium high and cook until the mixture becomes a deep amber color, about 6-8 minutes.
Stir in 1/2 cup seasoned rice wine vinegar or white balsamic vinegar and reduce heat to medium low and cook until the jam becomes thick. Stir periodically.
Remove herbs and bay leaves , season with kosher salt to taste and spoon the jam into a flip top glass jar. Set aside until it comes to room temperature then refrigerate until ready to use.
