Increase heat to medium. Add vinegar and cook 5-10 minutes until onions are completely cooked and translucent.
In small bowl, bloom gelatin in cold water, enough to cover them (3-5 minutes). Gelatin will be rehydrated and a jelly consistency. Strain all water from gelatin, add to fruit and onion.
Remove fruit and onion mixture from heat. Stir until gelatin is dissolved and add parsley. Cool.