In a medium saucepan, bring the water and 1/2 teaspoon of the salt to a boil. Stir in the couscous and raisins. Cover, remove from the heat, and let stand for 5 minutes.
Transfer the couscous and raisins to a large bowl to cool.
Meanwhile, in a small frying pan, toast the walnuts over moderately low heat, stirring frequently, until golden brown, about 5 minutes. Or toast the nuts in a 350 oven for 10 minutes.
Remove the nuts from the pan and chop them.
In a large glass or stainless-steel bowl, whisk together the lemon juice, 1/4 teaspoon of the salt, and the pepper.
Add the oil slowly, whisking.
Toss the carrots, the toasted nuts, the turkey, the arugula, and the remaining 1/4 teaspoon salt with the cooled couscous. Toss the salad into the dressing.
Variations:: Substitute three cups of shredded watercress or spinach leaves for the arugula.
Wine Recommendation: It may surprise you to learn that Germany and Austria make good red wines, racy with brilliantly pure berry flavors. Look for Germany's dornfelder or Austria's Zweigelt for a brisk change of pace.