Trim stems and base from fennel bulbs, reserving feathery fronds for garnish. Remove tough outer layer from each bulb. Cut each bulb in half through base. Cut out the small, pyramid-shaped core from each half. Place cored fennel, cut side down, and slice crosswise into 4 thick slices. Slice lengthwise into 1/4"-wide strips.
Combine fennel and orange sections in a serving bowl. Add olive oil, salt, 1/4 teaspoon pepper, and 1/4 cup olives; toss gently. Pile remaining 1/4 cup olives in center of salad. Chop fennel fronds, and sprinkle over salad, if desired. Add more freshly ground pepper, if desired.
Note: If you can't find fennel, use 1 small head Romaine lettuce, torn. Omit salt and olive oil, and use 1/2 cup of your favorite vinaigrette.