This hearty soup is flavored with fresh herbs, cumin, and ginger.
Cut one carrot in half; place in a medium stockpot. Add chicken, 2 quarts water, leeks, celery, parsley, thyme, bay leaves, and 1 teaspoon salt. Bring to a boil. Reduce heat to low; simmer for about 1 hour; skim off any scum. Remove chicken. Pass stock through a cheesecloth-lined strainer. Remove chicken meat from bones and slice into 1/2-inch-thick strips.
Rinse stockpot; return stock to it. Set over medium-low heat; add ground pepper. Dice remaining 2 carrots. Add carrots, tomatoes, cumin, ginger, and squash to stock; simmer over medium heat until vegetables are tender, about 25 minutes.
Meanwhile, bring 1 cup water to a boil in a small saucepan. Add couscous and remaining 1/2 teaspoon salt; cover and remove from heat. Let stand 5 minutes. Fluff with a fork. Stir in jalapeeno cilantro.
Add zucchini and chickpeas to soup; cook until tender, about 5 minutes. Add chicken meat; simmer to heat through, about 5 minutes. Adjust seasoning.
To serve, place a spoonful of couscous in a soup bowl; spoon soup around it and add a cilantro sprig and lime wedge.