1. To prepare dressing, combine first 7 ingredients in a medium bowl, stirring with a whisk. Gradually add oil, stirring constantly with a whisk.
2. To prepare salad, combine arugula and three-fourths of dressing in a large bowl; toss gently to coat. Arrange about 1/2 cup arugula mixture on each of 10 salad plates; arrange orange slices evenly over salads. Drizzle remaining one-fourth of dressing evenly over salads; top each salad with 3 olives. Sprinkle evenly with 1/2 teaspoon salt and additional black pepper, if desired. Serve immediately.