Pull the leaves away from the artichoke hearts, discarding the tough outer leaves and reserving the tender inner ones. Remove the choke and cut the hearts into thin, crosswise slices. In a large bowl, combine the chicken, sliced artichoke hearts, fennel and olives, drizzle with olive oil and lemon juice, and toss lightly. Taste to correct the seasoning. Divide the salad among individual serving plates, garnish each portion with artichoke leaves, wedges of preserved lemon, if using, scatter a few green olives over the top, and serve immediately.
Preserved lemons are increasingly available in specialty markets.
You can easily make your own. Cut 3 or 4 fresh organic lemons into lengthwise wedges, put them in a bowl, and toss them with 4 tablespoons kosher salt mixed with 2 teaspoons sugar. Pack the lemons and the salt into a pint jar and add enough fresh lemon juice to cover the wedges. Store in a cool dark cupboard for a week, giving the jar a good shaking once or twice daily. At the end of the week, transfer the lemons to the refrigerator and use within 4 to 6 weeks.