1. Using a sharp knife, cut the tops and bottoms off the oranges, then cut off the peel, removing all of the white pith. Cut each orange crosswise into ¼-inch slices and add to a mixing bowl. Cut each fennel bulb in half lengthwise and then thinly slice each half, adding to the mixing bowl along with the olives and arugula. Toss gently to combine.
   
   
2. In a small bowl, whisk together the Champagne vinegar, olive oil, salt, and pepper. Pour dressing, to taste, over the fennel mixture and toss to combine. Serve at once.

Notes: You can use any variety of oranges in this fennel orange salad recipe including navel, cara cara and blood oranges. It is also delicious with pink grapefruit. The nutty addition of walnuts or hazelnuts works great in this salad. You can prep the salad entirely several hours ahead, and then just toss with the vinaigrette right before serving.