How to Make It
In a small bowl, combine the grapefruit and orange juices with the oil and coriander. Season the dressing with salt and pepper.
Arrange the sea bass slices on a platter. Drizzle with the dressing and scatter the citrus sections, scallion and dill on top. Let stand for 3 minutes. Serve with toasts.
To make the citrus sections, use a sharp knife to cut off all of the skin and bitter white pith from the grapefruit and orange. Cut in between the membranes to release the sections.