Cut the fronds from the fennel bulbs and reserve some of the feathery leaves for later. Cut each fennel bulb in half and remove the cores with a sharp knife.
Fit a food processor with the thinnest slicing blade. Cut the fennel bulbs into wedges and place horizontally into the feed tube. Process in batches. Peel each orange, remove the pith with a knife, and slice. Set aside.
For the dressing: Whisk together the oil, juice, 1 teaspoon salt and the pepper in a small bowl. Place the fennel slices, oranges slices and arugula in a large bowl. Pour the dressing over the salad and toss together. Sprinkle with salt and add some fennel fronds for decoration.
2007, Ina Garten, All Rights Reserved