In a medium bowl, stir together oil, lemon juice, preserved lemon, garlic, and pepper. Thinly slice fennel bulbs crosswise, discarding fibrous ends, and stir into dressing. Chop enough fennel fronds to make 2 tbsp.; put in large bowl with arugula. Add fennel mixture to arugula and toss gently.
*Buy at a gourmet grocery store, make your own (see sunset.com), or order by mail from robertlambert.com ($12 for 8-oz. jar). Use only the rind; scrape out and discard the pulp.
Note: Nutritional analysis is per serving.