Couscous, the traditional accompaniment to many North African dishes, is a tiny semolina pasta, available in most supermarkets.
Heat oven to 450 degrees. Cut chicken breast in half, removing and discarding cartilage in center. Cut chicken into 1-inch cubes and place in a medium bowl. Add onions, celery, tomatoes, zucchini, raisins, parsley, and mint and set aside.
In a small bowl, whisk together stock, ginger, garlic, curry powder, chutney, 3/4 teaspoon salt, red pepper, and cornstarch. Pour over chicken-vegetable mixture and toss to combine.
Meanwhile, bring 1/2 cup water and remaining 1/4 teaspoon salt to a boil in a small saucepan. Stir in couscous and remove from heat. Cover and let stand for 5 minutes. Fluff with a fork, cover again, and set aside until ready to serve.
Fold the pieces of aluminum foil in half crosswise and unfold. Place half the chicken-vegetable mixture on one of the pieces of foil, 2 to 3 inches from the fold. Refold along the crease, enclosing mixture, and make a double 1/2-inch fold along the 3 open sides. Repeat process to make the second packet. Place both packets on a baking sheet and bake for 18 minutes. Divide couscous between 2 bowls. Open packets, arrange contents over couscous, and serve immediately.