In a small bowl, whisk together 2 tablespoons reserved grapefruit juice, olive oil, vinegars, honey, salt and garlic until honey is dissolved. In a large bowl, assemble the salad: Place endive on ...

Spoon the pickled-onion-and-grapefruit salad onto small plates and arrange the scallops around the salad. Drizzle with olive oil and serve at once.