Steps
1. Rinse the herring fillet under cold water and pat dry.
2. In a small bowl, mix the olive oil, balsamic vinegar, salt, and pepper to create a dressing.
3. In a serving dish, arrange the herring fillet and scatter the halved grapes around it.
4. Drizzle the dressing over the herring and grapes, ensuring they are well coated.
5. If using, prepare the quinoa or couscous according to package instructions and serve on the side.
6. Garnish with fresh parsley before serving.